What Do You Two Think?
by pricecheckgreen
Summary: Wherein Dr. W.D. Gaster takes two stray children under his wing on a whim and finds himself far more emotionally compromised in the end than he'd initially expected. The outcome of this story is grim—but then, are results worth more than the experience getting there?
1. Arc I Chapter 1

Arc I: Adoption

Chapter 1

* * *

Two small figures stopped for a moment inside a large, metallic building to adjust to the rapid change in temperature. Outside, they had been positively smothered in heat—in particular the larger of the two, who wore an over-sized, patched green jacket over his bony frame. Appropriate for the occasional draft and cold of the capital, perhaps—not as much so for the walkways of Hotland so close to broiling magma down below. It was a wonder the article of clothing hadn't caught fire on the dash over here.

There were no lights on inside, and the echoing sound their sneakers made when the two took a step halted their progress. Though the smaller of the pair—the one dearly clutching his companion's hand, looking about the total blackness in trepidation—was unable to read, the sign outside had said "Laboratory". Neither of them had ever seen such a word.

The silence was deafening, but the sound of footsteps from outside was terrifying, spurring them to act once more. The taller took the first step, fumbling in his pocket and pulling out a lighter. The flame wavered and made flickering shadows in his empty eye sockets, but stayed alight as he held it out around him, seeing walls and cluttered work spaces. This wasn't a home—not like the building they had been staying in the past few weeks. The one they had _thought_ was abandoned.

Careful to keep their bare feet from clacking as they came inside, the skeleton in the large jacket pulled the smaller behind a desk for cover, and held the fire up to his head.

"let's see what the damage is…"

His voice was soft when he spoke, as though relaxed, though that couldn't be further from the truth.

"SANS IS IT—" Sans had to clap a hand over the smaller one's mouth.

"papyrus you gotta be quiet okay?"

It couldn't be helped. His brother was younger, and seemed to have problems controlling the volume of his speech. Nonetheless, after a brief attempt at shouting YES, he nodded in understanding.

There was another tense period of silence where they listened to see if anyone had noticed their childish voices. The sounds they had heard while waiting at the threshold were still there but dimmer—farther away. Whoever it was, they weren't entering the building. They weren't pursuing the two any longer.

"…okay. –now hold still."

Papyrus obediently held his head steady as Sans looked over a few scratches on his cheekbone. They were minor—they'd heal without any scars remaining, no permanent damage. But they looked painful, and he could tell by the way his brother flinched when his fingers got near them that they stung. Fishing around in his coat pocket again, Sans pulled out a roll of duct-tape, peeling off a strip and carefully sticking it over the scrape.

"there. all better." He smiled wide and Papyrus smiled too.

"ALL BETTER?" The yell echoed off the walls and Sans hissed, pulling Papyrus to his chest to muffle out the noise of his loud apologies. Not waiting to see if there was a response from the outside this time, he grabbed his brother's hand again and ran into the darkness, only the lighter to show them where they were going as their feet clanged over the tile. There was a door to the left—Sans couldn't tell what was written on the front, and was momentarily stumped by a lack of hinges to swing it open on, but easily slid it far enough over that they could squeeze through.

The room was like a small box. Handing the lighter to Papyrus, he scrabbled against the handle and slide the door shut again, not wanting to see if Hotland's red light was coming through the entrance way.

"WHAT DO THESE DO?" Sans spun around, eyes narrowed and already bringing a finger up to his mouth in a gesture of silence. He saw Papyrus rubbing the strip of duct-tape on his cheek with one hand, and holding their only light source up to a panel of round buttons on the wall of the room.

" _shhhhhh._ "

Papyrus clapped his free hand over his mouth in alarm for only a second before adding, "SORRY."

Groaning softly, Sans strode over and took the lighter back, frowning up at the letters inscribed next to the shiny buttons. _3F, 2F, 1F, BF/TL._ They didn't make any sense. They weren't words.

Standing beside his brother whose brow was creased in thought, Papyrus recognized BF. He couldn't read but he knew that those letters meant "Best Friend". That was what Sans was to him. Without asking if he should—for he knew he would just get scolded again for making noise—he reached a small hand up and pressed the button next to those two letters.

The reaction from Sans was immediate—a startled look back in the smaller skeleton's direction, glowing white pupils tiny pinpricks. The reaction from the machinery they stood in was slower; the lights began to flicker dimly on, the door automatically sealing, and something high above them starting to whir into motion. Papyrus watched his brother run to the door and attempt to get it open before feeling himself grow queasy with the sudden sensation that the room was descending. Like gravity had begun to lessen around them.

" _what did you do_?"

"I PRESSED THE—" The machine stuttered in its climb downwards and Papyrus fell on his tailbone. Sans extinguished the lighter, stowing it away in a stuffed pocket and going to help his brother up. "ARE WE GOING SOMEWHERE?"

"i don't know." Sans opened the coat and pulled Papyrus into his arms, almost as though he was attempting to stow him inside. "i guess we are."

"IS IT SOMEPLACE NICE?" Over the sound of the room moving the high pitched voice didn't seem nearly as loud. Still, Sans made that same face that he had earlier, going to hold Papyrus' jaw closed with a soft _clack_ of teeth to get the message across.

The noise and the nauseating drop seemed to go on forever, the two of them holding each other and shaking, before finally with a disorienting halt the ride ended. The lights again flickered, as though dangerously close to shutting off altogether. Neither of them made a sound as they waited for some new figure to arrive and create the need for more running. More fear. They could have pressed another button—see if one of them would take them back to the world above where they had just been. But the thought didn't occur to them, remaining in place until finally, with a loud pop, the bulbs above them burned out.

Again Sans had to get out the lighter.

Papyrus trembling at his side, Sans approached the door. It seemed stuck, for a moment, and with a choking feeling in his ribcage the larger of the two thought that they might be trapped in this small room forever. But eventually it gave way, and they stumbled out into a much larger area than before. Just as dark, though.

Taking a few steps forward, a large door came into view, covered in several colored keyholes. Beside it on the left was a tall vending machine—one that didn't appear to be operational—and on the right a TV box suspended along the wall. When the brothers took a step near the TV box, glowing letters popped up, and they darted back in fright. Waiting for the writing to disappear before they could relax again.

Sans was prepared to take his brother's hand and run back the way they'd come when Papyrus tugged on his oversized sleeve, pointing up at the vending machine that they now stood close to. "WHAT DOES THAT SAY?"

Too overwhelmed to remember shushing him this time, Sans peered at the bags behind the machine's smudgy glass. Unable to hold the lighter too close, he had to squint in the darkness. Taking much longer than he should have out of the strange certainty that he was reading the labels wrong.

"pot-pop…t-ato…chisp..s?"

Papyrus patiently waited for Sans to be more sure about what they were looking at.

"…popato chisps."

Something about that didn't seem right.

"CAN WE GET ANY?"

Sans wiped his face with his hand, the sound of bone scraping bone the only noise while he thought. "i don't think it's on. and even if it was, we don't have any money."

Papyrus whimpered, looking down at the floor. Voice just the tiniest bit quieter. "I'M HUNGRY."

"i know."

Before the conversation could progress much farther than that Sans heard the now-familiar grinding of gears and the shudder of movement. The room they had just exited was going back up.

"—come on." He grabbed Papyrus' hand and pulled him down the left hallway, their tarsal bones _clack-clack_ -clacking as they jogged. More monitors lined the walls, each one popping up with text as they passed them by. Eventually they reached another room. The lighter couldn't show much—a few operating chairs, a few desks. Without many hiding places to choose from, the two of them huddled under a desk in the far corner, listening to the sound of the moving room.

"SANS, WHAT'S—" Sans clapped his hands over Papyrus' jaw again, shushing him and listening. The noise continued to go on for another minute before it stopped. Then, soon after, it started up again. Someone was coming down. It wouldn't—be the guards? They wouldn't have chased them all the way down here, would they?

Sans again flicked off the lighter and shoved it inside his pocket. Then he pulled his little brother inside the coat as though he was still small enough to be concealed in his arms, and he hoped that the darkness would keep them safe.

That is, of course, when the lights chose to dimly flicker on. The grinding noise stopped.

The two were well concealed from the side, but should anyone choose to walk in front of the desk, even look upon it at an angle, they would be seen for sure. There was only one set of footsteps coming from the hallway directly toward their room, but that didn't mean there wouldn't be others. Papyrus had started to tremble again.

A soft whistling became audible as the footsteps grew louder and louder. Whoever it was had entered the room, the whistles gradually transitioning to an odd, disjointed humming. Papyrus squirmed in the coat to try and get a look, and Sans only barely held him back. A chair creaked—he'd sat down at a desk farther away from theirs.

Only after a minute had passed this way did the two dare to look out at who they had thought was their pursuer.

It was another skeleton.

* * *

Dr. W.D. Gaster had come into work early that morning. He, of course, came into work early every morning. There was not a time when he did not enjoy being inside the laboratory building, to the point where several of his colleagues had speculated among themselves when they believed him out of earshot that he would live in or otherwise marry the lab if either option was available to him.

Of course the notion was ridiculous. Still, the idea of never having to leave did seem appealing when one thought about the treacherous, irritating commute through Hotland to get to and from his house. One that had been particularly irritating this morning, interrupted by guards hoping to catch a pair of thieves that had allegedly escaped into the area.

Well. No matter. Gaster paid little mind to such things, and he was well within the safety of his real home's metal walls, the gentle groaning of the support structure and the grinding hum of the elevator like an old friend welcoming him back. Inviting him to be productive.

Though as he'd deposited himself down at his workstation, looking at the keyboard through the holes in his hands as he typed in commands for his computer, something had indeed seemed…off. As though his day was doomed to hold many such interruptions as the one that had stopped him on the road.

Whatever it was, it was not something he could easily put his finger on, and he'd tried to ignore it. Tapping his fingers along the side of the desk, next to a mug that Asgore had gotten him with "#1 Scientist" on the side written in sharpie marker. There was no coffee in it.

Still, the odd sensation that there was an element of the familiar lab that was amiss, that was misplaced, continued. His legs felt as though they itched and so he stood, the small sound of bones popping as he stretched. Clacking his teeth together he paced in front of the operating chairs, eyes fixed on his shoes and hands behind his back, and ran through things in his mind.

Nobody would be here for a couple of hours. The building was empty. It had been locked since last night. None of the projects they were currently running were anywhere close to the stage where they could alter reality overnight, or even change color. Everything was operating as it had always been—out of date, inefficient, in need of repairs but somehow functional enough that his concerns were routinely waved off. Everything was the same.

But something was different.

He paused. The sound of his feet on the tiles stopped. And another sound became audible to him.

Ah. That was it.

There was the sound of erratic, quiet whimpering coming from somewhere in the room.

The noise had almost been drowned out by the hum of his computer hard drive and the high pitched whine of True Lab's poorly installed light fixtures. Frowning lightly, he glanced at his surroundings. Still everything seemed ordinary. The shadows below the operating chairs revealed nothing. Neither did those underneath the desk next to his. The faucets weren't leaking when he strode over to check them. A low grumble emanated from his neck bones underneath his turtleneck sweater. Then he turned around.

There under the far desk, glowing white eyes transfixed on his face like a Gyftrot covered in too many presents, was a young form in a battered green coat.

It hadn't even occurred to him that the noise might come from a _someone_ rather than a _something_.

Or perhaps even two somethings. There was a lump in the coat and the top of what looked like a second head poking out from within. Two skeleton children, one smaller than the other.

Like they were in a standoff on one of those cartoons that their new intern sometimes found at the dump, the three of them stared at each other. There was little movement save for the squirming of the smaller skeleton attempting to get out of the other's embrace to see better. This sort of thing had never happened before—the only people who would be interested in what went on down here had already been hired—and Gaster's mind was having trouble selecting appropriate action to take.

At least the whimpering had stopped.

Finally he began with a basic command for them to stop hiding. Whatever it was they were doing breaking in could be dealt with after that. But the two of them didn't move, the bigger one—who he assumed was the elder—with eyes as wide as dinner plates.

Realizing quite suddenly that it was unlikely either of them were able to understand wingdings, he sighed and switched to the more comprehensible aster font. "Get out from under there now. Please."

There was no reply, but the whimpering returned. Feeling a flash of irritation, Gaster crossed to the silent alarm button by one of the operating chairs, quickly pressing it. Hopefully the guards who had accosted him earlier about their two fugitives were still in the area and would get there before things became too—

Oh.

"Are you thieves?" His brow creased, growing somewhat more incensed with this disruption of his morning routine. "Why have you broken in? There is nothing that would be of value to anyone but me and my colleagues in here".

They had begun to shuffle out from under the desk, finally. The smaller one in a dirtied yellow shirt had a patch of duct tape on his cheek, which glinted somewhat as he spoke. "WE DIDN'T BREAK IN."

The volume at which his voice came out was a little surprising in some ways, although it did clarify that he at least was young—very much so. He didn't even seem to appreciate how much trouble they were in at the moment, as his older brother had to keep holding him back as he idly tried to walk.

"Oh? Then how exactly did you get in here?"

"THE DOOR WAS UNLOCKED." The one in green merely looked on warily, appearing unconcerned with the precise nature of the conversation. More like a cornered animal, in fact. It was…remotely puzzling. But, while his ability to judge people might be less than optimal due to his scant socializing, Gaster wasn't under the impression that either of them were hardened criminals.

"I see. I'll have to talk to our intern about that." He took a step towards them—what exactly he intended to do he wasn't sure, but he wasn't keen on letting them dart away like the green one looked about to do. "—The guards will be here soon, I am sure you can explain everything to them and—"

" _ **no"**_ Before he could register that the new voice belonged to the older brother, before he could even process anything past a sudden flash of blue, Gaster felt something hard smash very quickly into his face. The impact knocked him off balance, the whole world toppling for a moment, and then his back smashed into the sink. A searing pain swept through his right eye and he brought a hand up to cover it, the pressure doing little for his suffering. He heard the sound of bare bone on tile as the two of them began to run for the hallway, vision blurry from his unfocused left eye.

It was unfortunate for them that the way had already been barred by two soldiers in ill-fitting black armor.

After that point Gaster had both eyes closed, attempting to focus and think of what had just happened. There was arguing across the room—two young voices protesting their innocence and the sound of struggling, two other voices distorted and tinny saying…something.

He gingerly ran a bony finger over the socket and found a thin crack at the top of his eye, spanning about an inch up the side of his head. What had he been hit with?

Blue.

Taking a moment to once again refresh himself on his second font, Gaster called out "Wait a moment" just as he had begun to hear sobbing from the two children.

There was silence on the other side. Satisfied, he began to hoist himself up from his half standing position at the sink, again rubbing his eye. He couldn't open the lid very far—only about halfway. Perhaps a mite concerning but it was most certainly not at the forefront of his mind right now, forcing himself to push through the pain as he strode up to them.

"I would…" He paused as though to clear his throat, looking down upon the two young skeletons. "…I would like a moment alone with these children, if I may."

"Doctor Gaster, your eye…."

Another flash of irritation, glancing up at the monster in armor to the left. He had floppy bunny ears. "Do I seem concerned about my eye? Give me a moment with these two. _It is very important._ Do not forget who you are speaking to."

In all honesty the position of Royal Scientist carried with it very little real authority save for in scientific endeavors. Still, Gaster was very skilled in throwing his weight around as though it did, and after a moment of nervousness the two guards began to start back towards the elevator. "I will call for you if you are needed. Though I doubt you will be."

* * *

 **Author Note** : As an up-front warning I have no idea if I'll be able to finish this fic or not. I do want to-and I do have quite a bit written and planned out so far. But my inspiration and motivation has a tendency to flare up brightly and then quickly die, so we'll see how it goes. In the meantime, here is my contribution to the long list of fanfictions there are out there about Dr. Gaster and the skelebros. I hope you enjoy it.


	2. Arc I Chapter 2

Arc I: Adoption

Chapter 2

* * *

"i didn't mean to hurt your eye."

Sans' voice was rushed and trembling, and from the way that Gaster looked down at him—as though he'd temporarily forgotten that they could speak—it was probably harder to understand than he'd meant it to be. The doctor had been staring at them for the past minute, not saying anything. Some odd, far off look in his eye.

Or rather, he'd been staring at _Sans_. The look had begun to grow unnerving, and so he'd said the first thing that popped into his head.

"…What?"

"your—your eye?" Sans was shuffling Papyrus behind him protectively, but his brother's curiosity kept pushing him back up to the side. "i—i wasn't trying to—to do a—an attack, i—"

"You weren't?" Gaster's eyes both appeared to lighten further, his right eyelid going up as high as it was capable of now. Twitching slightly as it did. "That was magic, yes? You did that without trying to?"

"i—i mean i—" He had wanted him to stay away. All he remembered was absolute terror at being caught, being taken by the guards. And now he was painfully aware of the fact that he had probably just doomed the both of them by assaulting someone in authority. "i was just—please don't be mad, we didn't mean to be in here and i didn't mean to break your eye i'm sorry i'm really sorry."

"Sorry?" Amusement played over the adult skeleton's features. "Have I asked you to be sorry?"

Sans had no reply for that. It sounded like a trick question.

"We were discussing your blue attack." Sans felt his eyes shrink to pinpricks as Gaster reached out a hand to touch a finger to his forehead. "That's what it was, wasn't it? I'm afraid I wasn't in much of a position to observe."

"i-i'm r-really, really s-sorry—"

"SANS IS REALLY GOOD AT MAGIC!" Papyrus darted in front, fists clenched. Gaster took a step back, appearing somewhat off guard. "HE—HE'S REALLY GOOD AT SCARING BULLIES AWAY SO DON'T HURT HIM OR—OR WE'LL KICK YOUR BUTT!"

That only made Gaster laugh, a quick and sharp noise that was over as soon as it registered. Before Papyrus could say anything else Sans pulled his brother back with a "shush, papyrus", holding his mouth shut. Another painful silence ensued while the doctor appeared to be studying them again.

He quietly murmured something to himself in that bizarre language that he had used earlier. Sans fought down the fear and prepared for if he had to use magic again. Exhausted though he was, he wasn't going to let anyone get at Papyrus.

And then quite suddenly, voice light and inquisitive, Gaster said, "Well, I've heard both your names at this point. Mine is Wing DinGaster. Or W. D. Gaster. Or just Gaster-the one the guards used just now. Whichever nickname you would prefer, I personally don't care either way." When that was met with silence he continued, going again to rub his wounded eye. "Do you two have parents, by any chance?"

Papyrus would have shot up to answer but Sans was still clutching him in a death grip. Again neither of them spoke.

"It would do you well to answer questions when they are given to you."

"—no." They had been asked this question before. Usually in situations that directly preceded having to run to a new place to stay. "it's always just the two of us."

"Interesting." Gaster leaned down to get a better look at Papyrus, though he had the good sense not to touch _him_ at least. "Where do you live, then?"

"n…nowhere. sometimes we—have places but they don't last."

"I see." He stood up straight again, index finger going into his mouth like the end of an eraser. Not knowing the purpose of these questions, the fear and anxiety that had pervaded Sans' judgment slowly slid into his usual suspicion. Adults were not trustworthy—even the ones who gave them food or a blanket to wrap around themselves never gave the whole truth. "No parents, nowhere to go, no options…"

Sans pulled his brother closer to himself, backing away just a little bit. Not sure where he planned to go but he didn't like the way they were being looked at. Like they were specimens to be observed and not—not children.

"I have a proposition for the two of you."

The resounding "no" that should have immediately followed the suggestion was drowned out by Papyrus' sudden "WHAT'S A PROPOSITION?"

Gaster tapped his chin with one long finger from the free hand that wasn't periodically rubbing at his eye. "A proposal? A suggestion? An offer, if you will."

"ARE YOU GIVING US CANDY?" Papyrus still remembered the one occasion where they had met a nice lady who was giving out monster candy, only for Sans to push him along to keep him from getting any. He wasn't still mad about it but he did give his brother a bit of a look after speaking, as though to let him know that he still remembered that day.

"…I…There could be candy involved? I will have to check my pantry…" The doctor shook his head, speaking up again quickly before the younger skeleton could interject. "No, my offer is not candy. I was thinking that since you have nowhere to go—perhaps you would like to come live with me."

Today didn't seem real. Sans broke someone's eye socket and instead of being punished for it they were being offered a home. –It couldn't be real. It wasn't. It was some sort of trap and if he wasn't careful they'd fall into it headfirst. Papyrus' eyes lit up like ceiling stars and he rushed forward as though to see their new benefactor better. He always had more enthusiasm than sense. The doctor seemed pleased by that development, clapping his hands together.

"YOU MEAN WE GET TO—WE—"

"what do you want in return?"

There was silence for a moment, Sans moving back to retrieve his brother. He could tell the adult wasn't expecting a child to ask a question like that. Most of them didn't.

"Well well, aren't you shrewd?" Gaster was still grinning but this time as he directed his attention back towards Sans the expression looked different. Meaner. "I do want something from you, yes. But that…well, that wouldn't be for a long time. At least a year—probably longer." He paused a moment in thought, tapping his chin. "…Yes probably longer. Everything's really in the theoretical stage... –All you would be agreeing to at this point would be to come live with me. Where I can keep an eye on you."

"where you can keep an _eye_ on us?"

"Did I misspeak? Yes, I plan to keep an eye on you." His gaze didn't waver, tilting his head just a little. "That is what one does as a parent, is that not correct?"

Sans' eyes narrowed. The wording felt wrong to him.

"If you don't like my offer, you are free to refuse." The doctor said quite suddenly, the mean grin growing wider. "And considering the way our king usually handles things, I'm quite sure you won't be put in prison for your minor crimes. He's very lenient."

"then—"

"— _But._ " Instead of looking at Sans directly he leaned over Papyrus. "I think the odds of you two being… _separated_ in foster care would be awfully high."

"NO!" Papyrus started to tremble, gripping Sans arm hard enough that if he had any blood it would be dripping down his sleeve. "SANS NEEDS ME WE CAN'T BE SEPARATED!"

"Then you've decided?"

"—wait." Sans almost choked. Everything was going too fast—he couldn't process what was going on. Papyrus was pulling away from him and towards the scientist, practically bouncing on his feet, and all the elder brother could do was drown in his helplessness.

"YOU MEAN WE GET TO STAY WITH YOU?"

"Oh yes, that's the idea. Of course I'll have to get approved and everything but I'm sure that won't be too difficult."

"—wait—"

"AND IT'LL BE A REAL HOUSE WITH A REAL BED AND YOU WON'T CHASE US OUT WHEN YOU GET BACK FROM VACATION?"

"Yes, yes. Precisely. I'm glad you're so enthused, child."

"w-wait—"

"It's settled, then." Sans could tell he wasn't being totally ignored but rather being glossed over, and it choked him somewhere deep in his chest. The air of finality was strong as the man glanced once more at Sans before grinning down at his baby brother. "We will go discuss things with Asgore and have you cleared of your charges. Come along, children."

Without really waiting for either of them, the youngest skeleton began to head for the hallway. This was a dream come true for him. Exactly like one of his dreams, actually, with only a few minute differences in location and the players involved. Sans was always cautious—always urging him to wait when something exciting was on the horizon. He didn't want to listen this time.

The other two lingered behind somewhat.

"Did you have something to say, Sans?"

As Papyrus walked on ahead, ever full of boundless energy, Gaster placed a hand on San's back. Perhaps in an effort to be comforting, or perhaps to push him along so that he didn't fall behind them. From the slight pressure on his shoulder blades the child could distinctly feel the holes in the man's palms, and it made him shudder.

But they didn't have a choice.

Papyrus needed a home.

They couldn't stay on the run forever.

"…no. i guess not."

The scientist smiled wide. "Then let's get going, shall we?"

* * *

The pair of children, despite the younger brother's initial enthusiasm, had seemed anxious on the way to Gaster's home after smoothing things over with the adoption. Constantly asking questions about what the building was like, looking warily at the paths that he took to get there. It almost wore on his patience, but he had a soft spot for curiosity and so let it all slide, answering while occasionally moving his hand back to his eye. Not because it still hurt, although it did, but because the feeling of the crack over his face was foreign and intriguing.

For all their sakes it was fortunate that they made it there within a good span of time. His home wasn't too big—it was actually rather small, most certainly much smaller than the lab at Hotland. At the same time, compared to the cramped, squeezed together houses that comprised much of New Home, it was a mansion.

Gaster made a little satisfied hum as he unlocked the door. Oh he'd have to work tonight to make sure they had adequate rooms set—he had the space, he just needed to shift some things around—but overall this was a good day. Shame that he couldn't get any lab work done, the legal matters had taken up so much of his time.

He was about halfway through the living room when he realized that the boys were still standing there at the threshold, not moving. Their little shadows didn't accompany his as he walked to the light switch.

"…Children? Are you coming?"

They looked up at him before seeming to remember themselves, scuttling inside and closing the door just as he got the dim, fluorescent ceiling fan to flicker on.

"—Well!" He clapped his hands together, the sound dull and quiet through the holes in his hands. "This is your new home."

"our new home in new home?" Sans was grinning as he spoke. Gaster wasn't sure why.

"Yes, that is correct."

"…right."

"I will be working on getting your rooms ready." Gaster went to hang up his coat on a rack he'd installed near the door. There were a few signs and posters that he'd made out of boredom in the living space. All of them in wingdings. "In the meantime, why don't you two—"

"'room _s'?_ " Sans and Papyrus exchanged a look, the meaning of which he couldn't fathom. Then, Papyrus spoke up:

"MR. GASTER ME AND SANS DON'T NEED TWO DIFFERENT ROOMS? WE USUALLY SHARE EVERYTHING."

Gaster merely waved dismissively at that, walking back over to the two of them. "You might not think you need two different rooms now but trust me, when you get bigger you'll want your own space. It's better to separate now while it's easier to adjust. -Your coat please?"

Sans blinked, glancing around a little as though he didn't know at first that he was being addressed directly. "—w-what?"

"Your coat." Sighing lightly, he reached down to take the ratty and patchy thing off of the small skeleton's thin shoulders.

"—that's alright i thinki'dratherwearit." Sans struggled to keep it on, clutching at the fabric and actually managing to tear off a piece of duct tape keeping the stuffing in.

Odd.

"Don't be ridiculous. You must be burning up in that." With a hard tug, the jacket came off, and Sans was left standing there in a dirty yellow shirt that greatly resembled the one his brother wore, eyes tiny pinpricks. It looked as though he would have to procure some new clothes for them—the state of their current ones were abominable, although he would spare his new charge the embarrassment of taking the shirt off right now as well. "Isn't this better?"

"SANS?" Papyrus interrupted before a response could come, looked over his brother as though he was seeing him for the first time. It occurred to Gaster as he felt the ratty jacket in his hands that perhaps Sans had never taken it off in front of him. Perhaps that explained the odd attachment to it. Then the younger brother laughed, putting his arms around him. "I ALWAYS THOUGHT YOU WERE SO MUCH BIGGER THAN ME BUT IT WAS JUST THE COAT."

"hah…hah…" The physical contact appeared to be doing some good to the inexplicable panic that had seemed to overtake Sans when the coat was taken, and so Gaster moved his attention to the offending article in question. Now that he had it in his hands he could tell that there were various articles in the pockets. Duct tape, a lighter, a few wrappers covered in some sticky substance, a ketchup packet or two—mostly garbage with some useful oddities in the mix. He'd clear out the pockets later to make sure he didn't dispose of anything of value.

"I will have to get you some more suitable clothing later, but for now we will focus on getting you acclimated to the house." He hung up the coat on a hook and then turned back to the two of them, nudging them towards the kitchen. "First thing would be nourishment, yes?" The king and his wife had provided some tea and snail pie when they had visited to discuss matters, but that wasn't exactly a full meal. "You two don't, ah, if you'll pardon the assumption, look as though you get to eat much. "

Skeleton girth was difficult to ascertain, as they had no fat storage of any kind. Generally one could make assumptions by bone thickness rather than overall mass—and theirs were very thin bones indeed.

"I EAT SOMETIMES BECAUSE SANS GIVES ME FOOD?" Papyrus moved to hold Gaster's hand as he led them to sit down, and for a moment he wasn't sure what to make of that, not immediately pulling away so as to avoid being impolite. "BUT THEN ALL SANS HAS LEFT IS THE CONDIMENTS?"

"—we—" Sans was staring somewhat intently at the fridge, mouth in the shape of what might have been a smile or a grimace, and so Gaster extricated his hand to continue preparing them something. Inside the fridge he had leftovers from a local restaurant that he tended to frequent whenever he had the time. "—we don't have money. so we don't get much to eat."

"Well, that won't be a problem here." Admittedly, he wasn't a particularly good cook himself, but his employment did give him more than enough to afford purchasing better quality meals whenever he pleased. It shouldn't be too much strain on his budge to pay for two more, especially with how little he tended to eat for himself anyway.

There on the back shelf sat the tinfoil wrapped box. Gaster pulled it out, careful not to spill any of the contents. "You will have to forgive me for being so unprepared but you two are a quite sudden development—" Setting the box on the counter he prepared his stove for reheating it and a small tray to set out the leftover food—bacon and cheese quiche. "—You two are not allergic to anything, are you?"

He glanced back in time to see the two of them giving each other incredulous looks. Were they not familiar with the word?

"…no. pap's not allergic to anything."

Before he could form the words asking who "pap" was Gaster realized it was a nickname. "-And yourself?"

"…nah."

The assertion didn't feel legitimate. He had a nagging suspicion that he was going to get a lot of half answers out of the older brother, and resolved to talk to him alone later. Make clear that he expected to be given full and accurate information at all times. Otherwise how could Gaster be expected to reciprocate in kind?

"SANS IS ALLERGIC TO TEMMIES."

Papyrus, refreshingly, seemed too young to understand the concept of lying.

" _shhhhh."_ Sans gave a hiss of irritation and tugged on his brother's shirt collar. " _he doesn't need to know that."_

"Noted, but true. There are no Temmies in this quiche." Gaster slid the tray into the oven and set a timer, walking back over to sit across from the two of them. He steepled his fingers. Sans appeared to be trying to stare at his damaged eye, and Papyrus was looking directly at the holes in his palms in something that might have been discomfort and wonderment rolled into one emotion.

There was silence. Perhaps he should be more direct.

"Tell me about yourselves."

* * *

 **Author's Note** : I'm not entirely sure how I want to go about an update schedule. I think it would be better in some ways to have a weekly update schedule, but I also am not sure if I can get chapters out on a weekly basis like clockwork with everything else I have going on in my life. So for now I suppose I'll be going on a "if I have it done" basis which means that sometimes it might update early and sometimes it might update late. -We'll see.


	3. Arc I Chapter 3

Arc I: Adoption

Chapter 3

* * *

Papyrus was too excited to sleep, that night. He'd sat on the bed—a real, comfy, warm bed—in his new room and stared at the door, waiting for it to be daytime. He knew he was supposed to get some rest but this day had been too full of change for him to possibly shut his mind off, even if he wasn't sure himself what he was thinking about.

That, and…

Well.

It was a little scary being in this big room all by himself.

It wasn't that he thought there would be any dangers while they were in this nice house with this nice scientist man who had come to rescue them out of the blue. No, he wasn't-worried about that. It was just that he'd never been apart from his brother. Not for more than a few minutes at a time. He always slept curled up in his arms so that they could both share the warmth of the coat while they shivered in the street, or wherever it was that they happened to spend the night. It wasn't cold in the house, not at all, but the closeness was distinctly absent and it made it hard to relax.

Perhaps Sans felt the same way.

Maybe he was having trouble sleeping too.

As quietly as he could, Papyrus slipped out from where he'd been tucked under the covers and took a few steps towards the door. Nobody came to put him back into bed.

Sans' room was right next to his, and the door easily swung open when he tried the knob. To his dismay, upon walking in and getting a better look he saw that his brother _was_ asleep, curled up into a little ball on the center of the mattress and not waiting there staring up at the ceiling like he had been.

Perhaps though it was better that they didn't have a chance to talk to each other. Papyrus knew he tended to yell a lot, and he didn't want their new dad to get upset that he was in Sans' room instead of the very nice other one that he'd so thoughtfully cleaned up for him. ...Even if they'd told him more than once that they wanted to share a room...

Sans barely stirred as he climbed up onto the mattress, trying not to be too disruptive while squirming close enough to feel more secure again. To his surprise, as though aware of his presence even while dreaming, Papyrus felt an arm on his side, Sans' body curling up almost protectively around him. All the while continuing to snore.

It didn't put him to sleep but it did at least allow him the luxury of resting, closing his eyes and breathing softly through the night.

Gaster hadn't even seemed upset the next morning when he found Papyrus in there with Sans rather than in his own room like he was supposed to be. It had appeared to intrigue him, rather. Not that his expressions were easy to read, especially with the bad eye that he didn't seem concerned about at the least; he hadn't even put any duct tape on it.

"It looks as though we are going to need a small adjustment period." He'd woken them both up and told them to get ready for breakfast as Sans blinked in confusion at his brother, who had not been there when he went to sleep. "Perhaps every other day? …I could lock your rooms from the outside?…" The man seemed to do a lot of muttering to himself, arranging some new clothes out for them on a chair near the door and—Papyrus actually felt his heart leap at that because no one ever gave them gifts.

After Gaster had left to go finish getting around himself, Sans put on his customary grin and said, sleepily, "bro you could have woken me up. it would have been fine."

"BUT YOU WERE SLEEPING. AND I WAS SUPPOSED TO BE SLEEPING."

"i'll have plenty of time to sleep later. like now for instance" Sans winked and went to fall back onto the bed, smile still stretched wide on his face.

"…WAIT, SANS. WE ARE SUPPOSED TO GET UP FOR BREAKFAST."

"nah."

"SANS." He pulled on Sans' feet to try and get him out of bed, but he was too small and weak to actually achieve much. "WE HAVE TO GET DRESSED."

"naaah."

"YEEEES. WE ARE GOING TO GET DRESSED AND HAVE REAL FOOD."

"we had real food yesterday."

"SAAANS." His hands slipped on his brother's ankles and he tumbled to the floor, crying out in a mixture of pain and ridiculously extreme frustration. Sans finally started to sit up at that, but at that point Papyrus was already pulling off his grubby, ugly clothes and changing into the clean, white and black outfit that Gaster had gotten for him. He'd just go get breakfast by himself. "JUST NEVERMIND."

"hey come on, pap."

"NO YOU RUINED IT." The shirt was a little too big for him, and it took him a moment to realize that he was wearing the one that had been intended for Sans instead. He scrambled to amend his mistake so he could storm out like he wanted to, and he heard the soft thump of his brother's feet on the carpet.

"hey come on you know that sleep just comes naturally to me."

"SANS."

"i could do it with my eyes closed."

" _SANS."_ In spite of himself he grinned as he feebly shoved his sibling. While pulling on his own shirt one of his arms go stuck in the sleeve, and Sans helped him fix it. "YOUR JOKES ARE TERRIBLE STOP."

"yeah but i get the feeling they tickle your funny bone."

Papyrus practically shrieked to keep from making any kind of laughter and threw the remaining set of clothes at Sans. They hung over his skull for a few moments while Papyrus looked curiously at some socks that had also been included with the rest of their new things. It had been a very long time since they'd owned any of these. The last pair had torn about 3 holes before finally the two of them had given up and thrown them out.

They felt fuzzy and soft against his bones and he tried wiggling his toes with them on to see what it would look like.

"…he's not a very colorful guy, is he?"

Papyrus glanced back. Sans had pulled the clothes off of his head but was still dressed in the ugly yellow shirt that they'd gotten from the garbage. Just staring down in that odd, empty way that he did sometimes.

"I THINK HE JUST NEEDS US TO HELP HIM PICK OUT SOME BETTER THINGS." It was true that everything about Gaster's fashions choices was…monochromatic, but that wasn't necessarily a bad thing. Everything was clean and organized and Papyrus could respect that. He just seemed like a man who was very focused on particular things and not much outside of that. -Maybe he didn't know that they were important.

"…i guess."

Sans finally started to get dressed after that, although painfully slowly. Papyrus almost did get fed up and storm out on him. But what were brothers supposed to do if not put up with the idiosyncrasies of their siblings? So he pouted and folded his arms, pacing a small circle into the carpet until they were both ready to head out together.

Everything looked a little bit smaller in the light of morning, but that was alright. It was cozier that way. Gaster was nowhere to be seen, the front door slightly ajar in a manner that suggested he had stepped outside for a minute. Papyrus hoped that he hadn't left to get breakfast without them.

As they walked into the living room he caught Sans glancing towards the coat rack. Their jacket—the green one—wasn't there. As their new father made his way back inside, humming tunelessly to himself, Sans went to grab his sleeve.

"where's breakfast?"

Gaster said something unintelligible before clearing his throat inclining his head towards the door. "We're going out to eat. I'm not much of a chef and there's a breakfast place up the road that I think you two will both enjoy."

Another thrill of pure joy when through Papyrus' body and he tugged on his brother's arm. "DID YOU HEAR THAT WE GET TO GO INSIDE AN ACTUAL RESTAURANT. –AND NOT GET KICKED OUT."

Sans smiled back at him in a manner that looked like he might be slightly queasy before glancing back at Gaster. "if we're going out, where is my jacket?"

Rather than actually answering the question the man lightly pulled his sleeve away, waving a little dismissively and heading back for the door. "It's not that cold out today, especially now that the fabric you're wearing isn't threadbare. You won't need a jacket."

Sans made an uncomfortable whine, shoving his hands in his new pockets. "i know I don't need it, but can I please have it back? i don't like—not wearing it."

Gaster shrugged. "Well, that's impossible. I threw it out already."

"you did….what?"

Sans' pupils disappeared entirely, and Papyrus cringed because he knew what it meant when his brother's eyes got like that.

"Do you have some sort of hearing problem? Am I not speaking correctly?" It wasn't sarcasm but genuine inquiries, apparently oblivious to the some very obvious signs of distress. "I sent your old jacket to the dump. I wouldn't be surprised if that's where it came from in the first place, the old thing smelled like—"

" _ **bring it back.**_ " If skeletons could cry, it was plain by the tremor in Sans' voice that his sockets would be full of tears right then. " _ **why did you get rid of it bring it back right now.**_ "

There was a slight pause as their new dad seemed to process this, tilting his head a little bit and frowning in his good eye. "…Are you concerned about the items in it? –I have put everything that wasn't trash in a box for you, actually. It should be there by the stairs—"

" _ **no i don't care about the—**_ " Sans did actually look back towards the stairs at that, and to Papyrus' horror instead of being grateful for that he dashed over and kicked the box hard enough to upend its contents. Then he ran straight to his room and slammed the door shut.

Gaster ran after him but at that point the door was clearly locked. Papyrus felt his soul shudder with each rattle that he made trying to open it. "Sans? Sans!"

Seeing his brother this upset—this openly upset—was rare. And for the moment he was grateful for an adult nearby who knew to take at least some kind of action. Even if it was probably wrong.

"You have to come out sometime. What do you intend to do in there?"

The reply that eventually came was bitter and quiet. "sleep."

"Child, you cannot possibly sleep all day."

"just watch me."

"I cannot watch you, you will not open the door."

Nothing more was said from the other side, and after about a minute of waiting he seemed to give up, returning to the living room and lost in his own thoughts again.

Gaster might have felt guilt at the emotional state he had clearly reduced the older brother to, if he didn't seem to be so overwhelmed with complete bewilderment as to what he'd done wrong in the first place. "But I don't understand, the coat was _worthless_." He glanced helplessly at Papyrus, one finger slotted into his mouth somewhat as though it was an eraser to chew on while solving a math problem. Papyrus couldn't explain—he understood but he didn't know how to put that understanding into words, not yet. "Did he really care about it that much?"

When he received no immediate answer to that he moved his finger to his chin and closed his eyes. There were more words that came out of his mouth but they were all in that language that Papyrus couldn't make sense of.

Finally Gaster said, voice tinged with frustration, he went to take his hand and led him to the door, only stopping to mutter to himself without input, "I suppose we will go have breakfast by ourselves then."

* * *

Their " _new dad_ " had been correct in saying that Sans could not sleep all day.

This was, of course, because Sans had not been sleeping at all. Although he did try to at several points. There was too much light in the room now that the rest of the capital had been waking up, the curtains insufficient to block the glow of street lamps. Instead of passing through the hours in oblivious dreams he had to count off the minutes in his head, getting up every now and then to look at the clock and make sure he was on time.

After only a couple hours had passed he realized how hungry he was. Papyrus and Gaster had left him some breakfast outside the door earlier. Too furious with both of them for reasons he didn't think he could explain to himself, Sans had left it there. But the emptiness in the core of his being demanded food, and so he crept over to take the cold eggs and hotcakes when he was sure nobody was watching his door. They tasted alright, in spite of everything.

It wasn't a bad room. It was warm and comfortable and safe. It was better than sleeping on the street. But the walls made him feel trapped. He's done so much running away in his life. And now, though it seemed there was no need to, it was unbearable that he couldn't. Not easily. It wasn't like he could phase through plaster.

Things hadn't been going his way, that's all. They never did but this time it felt like it was intentional on someone's part.

More of the day passed, interrupted once more by Gaster asking through the door if he wanted to go to lunch and answered only with stony silence. He continued staring up at the ceiling that way, and the negative feelings that he'd had slowly melted into a peaceful calm.

It did feel silly, getting so upset over something that…actually _was_ from the dump. Everything that they had was someone's trash. But when he thought about how it had been taken from him, how it hadn't even mattered the way he felt about it—didn't even _occur_ to the person who'd claimed yesterday that he'd take care of them—

That was what made him lose his temper, he supposed.

Or maybe that was an excuse for being irrational about his security blanket getting stolen away.

Heck if he knew.

All this thought and time wasted lying down he was starting to get hungry again. He felt a little guilty, suddenly. He'd left Papyrus all alone with a stranger. Granted, a stranger that was obligated to keep them safe, but still. Abandoned his own brother over something stupid. Maybe he should get up and go check, forget his dumb proclamation that he'd sleep all day.

When he heard another knock at the door all of his trepidations came back in full swing and he frowned, willing the other person to go away, whoever it was. There was no follow up, however. No voice on the other end.

Thinking about how things had gone with breakfast, he sighed and quietly got off the bed. Preparing a nasty scowl in case his new guardian was still standing there.

He was not.

In front of the door when he swung it open was a little grease-stained bag, and a gray box. The bag smelled amazing—even in his current emotional state he could appreciate that, and he quickly pulled them both inside before locking himself in again. Lunch, he discovered with some mild surprise, was a hamburger, warm and juicy and covered in fixings that threatened to spill out of the bun. There was too much mustard but he wasn't complaining, wolfing it down with alacrity and getting a mess all over his face and his new shirt.

Not that he was shedding any tears over that.

Sans sat there for a minute, wiping the hand covered in mustard on the sheets and lightly scraping ketchup off the other with his teeth. A stray pickle had made its way down into the bottom of the bag, and he popped it into his mouth. "Dill-icious."

…It wasn't as funny when he was alone.

He told himself that Papyrus was the one who had suggested getting him a hamburger so that he could feel grateful about it without any guilt. Of course, that still left the box, which he had deposited just inside the entrance to the room and left there.

It didn't look like a present. It was just a plain, short gray box. There was some writing along the top and sides but he couldn't read much of it. There were too many words he didn't recognize. Considering the color scheme it did look like something that Gaster would have gotten, so half of him was inclined to just throw it down the stairs.

But then maybe it wasn't gray on the inside?

What was it supposed to be? Another shirt?

He crept over to it lying there on the floor and tried again to make out what the words meant. One of them—one of them looked like a logo. So it had to have come from a shop. Maybe something they'd gotten while they were out for lunch.

Curiosity overriding spite, he slipped his fingers under the lid and pried the box open.

He carefully lifted the contents out, the fabric unfolding around his hands under its own weight.

A few sizes too big.

Just like the coat had been.

Scowling with all of his teeth showing, Sans crumpled the brand new piece of clothing back into the box, dented the lid as he slammed it back on, and tossed the offending object in his new closet.

* * *

 **Author Note** : One minor difficulty with this fic is that I often write as inspiration comes for the segments I want to include. Sometimes this means I work more on later chapters than the ones I need to post next. I think at least the later ones will start coming faster, since a lot of them end up becoming partially written? We'll see.

Thank you so much to those of you who have left reviews, the kind words mean a lot. I have a tendency to overthink things and get stuck midway through a fic but I'm going to try very hard not to do that here because there are parts I'm excited about.

In the meantime so ends Arc I. It's a little on the short side-some will be longer than others.


	4. Arc II Chapter 1

Arc II: The Lab

Chapter I

* * *

"No, no…it's all the same words. It's just a different way of pronouncing each letter."

The concept of language among monster kind was difficult to teach in general because it wasn't really Gaster's field of interest. He'd never bothered to question _why_ or _how_ he had two font systems to his mind, just placidly accepted that it was the case and instead interrogated the makeup of the soul, and the physics of magic. So now of course he only had vague notions of how it worked to explain to his new children, and the expected roadblocks had arrived.

Not that it was necessary for them to know. He could communicate just fine already. But a small part of him that he hadn't heard from in ages insisted that it was…important.

With a small stick that he'd crafted into a pointer he tapped the symbols he'd scrawled up on a poster for them and wished they weren't so fidgety about having their faces touched. He could coax their jaws into forming the proper sounds if they weren't, and it would be so much simpler than trying to describe with language a tactile concept.

"-You're just speaking nonsense right now."

"it sounds exactly like nonsense when you say it."

That brought a slight scowl to Gaster's face, and he lightly tapped Sans over the head with his pointer. "Well it is _not_ nonsense. It is merely another way of saying things. I don't understand why you're having so much trouble with this. I was born speaking wingding."

"I WAS BORN SPEAKING ENGLISH."

While Sans might have been failing to pick it up at least in part because he wasn't trying, Papyrus' difficulty wasn't a lack of effort but a misunderstanding of what they were trying to do entirely. Towards him the scowl relaxed, and instead Gaster patted him on the head.

"No, no dear boy it's still English. It's just a different way of encoding the language into letters."

Perhaps he should use more simplistic terms. They were still children after all. But he didn't really know how to explain things to others in a simplistic way. Usually his coworkers either got what he was saying or their understanding wasn't necessary to the success of whatever he was undertaking.

"…BUT IT DOESN'T SOUND LIKE ENGLISH."

"Try thinking of it like an audio cipher."

"A CIPHER?" Papyrus cocked his head in a manner very similar to the puppies living in Snowdin, Sans picking at some leftover breakfast sausage stuck in his teeth. "WHAT'S A CIPHER?"

"It's like a sort of letter puzzle—"

"A _PUZZLE?_ "

The word seemed to excite him to a strange degree, and Gaster filed away a note in his mind to address that later. It was a skill area worth exploring, in his opinion.

For now he merely said, "Calm down, Papyrus."

"even if it's as clear a translation as you say—" Sans had this irritating habit of appending statements to information that his caretaker had given him as though he believed it to be false. He barely offered a glance the boy's way, feeling a small and brief flash of spite. "—that still doesn't explain how we're supposed to actually _say_ any of it. your voice gets all—weird."

Gaster merely sighed, finally, and put a hand to his forehead. "Then I suppose even if you cannot master being able to speak it there must still be hope for teaching you to know wingding when hearing it. Especially as I so often tire of aster." After a moment though he smiled, going to place his hands on both of their heads in a comforting gesture. Or one he hoped was taken that way, at least. "[Then we will all understand each other.]"

From the expressions on their faces he could tell only a word or two of that got through. …Ah well. Patience was a virtue.

At that moment a beeper went off in his pocket. Startled, he had to fumble with the buttons on his coat for a minute before getting the darn thing out and checking the message it was programmed to say. Muttering a curse to himself in wingding—which was at least one benefit to their not understanding yet-he then glanced down at his charges. "Come on, we're going to be late to work."

Obediently, they got up from the small desks he'd arranged for them and ran to get their coats. Or rather, _Papyrus_ ran to get his coat. A shiny orange jacket that said "Slim Jim" on the back, with the "Jim" part fervently crossed out and replaced with "Papyrus". Sans of course was still in his plain white T-shirt that he never added to regardless of how windy it got in the underground, and he merely ran to the door.

Oh well. Couldn't say Gaster hadn't tried. Might as well have saved his money, though.

It was just lucky for the little smart aleck that it was a relatively warm day.

He didn't need them in the lab—not _yet_ , anyway. But they were too young to leave alone in the house, and too volatile to trust with any old babysitter. That is what he had ascertained in his time as their guardian. So for the past few weeks now, Gaster had been taking the children to work with him. Sometimes there were problems—Papyrus could be distracting and Sans initially had problems keeping his hands off the projects—but overall his coworkers had taken to them quite well, and it kept them entertained. It also got them used to the environment, which was very good.

He wanted them to be able to relax when his planned experiments involving them started for real.

The path to Hotland from New Home wasn't particularly long but it was devilishly complicated. After making some recommendations to Asgore there had been some progress in developing much more straightforward paths—the risk of humans coming down to the underground was far outweighed by the massive inconvenience to anyone commuting through the area—but it still took a little bit of time and frustration to navigate.

"…COULDN'T WE JUST USE THAT BOATPERSON?"

" _No._ "

All in all they ended up about five minutes later than was usual. Usual for Gaster, at least. There were no real penalties if he didn't make it in to the lab on time, being the Royal Scientist, but it set a bad example for everyone else.

There was no one in the main floor of the building as they strode inside, shoes clacking with each step. That meant that everyone had already made their way down to True Lab, and so a little more hastily than usual he hustled them into the elevator.

Initially—the work day after he had adopted the boys—Sans and Papyrus had stayed in the gathering hall, not talking much to anyone but each other, keeping confined to the room while occasionally looking at the data entry station inside it. As a few more days passed they had become more and more bold, until they ended up splitting off to pursue their own personal interests the second Gaster allowed them to explore autonomously. As of yet he hadn't been paying too close attention to what they did—perhaps it would have been in his best interest to but as of yet most of what they did do was observe and occasionally pester his coworkers.

* * *

Or perhaps it would be more appropriate in cases of people like Arbogast to say that his coworkers pestered _them_?

"I got a surprise for you two!" The monster chirped to them that morning, jagged mouth held in an odd fashion. Papyrus had very quickly taken to most of the people who were there in the lab—new friends, he'd called them—and despite being one of the strangest creatures the two of them had ever seen, Arbogast was no exception. It helped that he always conducted himself with utmost thoughtfulness and good manners, something that scored well on the younger brother's list of admirable traits.

Sans on the other hand tended to be a little wigged out by the fact that he had no actual body, and just appeared to be a head sprouting out of the ground. It didn't make any physiological sense to him. He appreciated much less the fact that somehow he was able to keep a labcoat on despite not having any shoulders to speak of.

"yeah? …where are you keeping it, in your mouth?"

"Yes."

Naturally.

He opened his wide maw and deposited in front of them two small cubes. Each side was a grid of nine squares, all of them assorted colors. "I found these in the dump. I hear human children like to play with these so I thought maybe skeleton children would too."

While Sans stared down at them in mild, concealed disgust, Papyrus eagerly scooped up the blocks, looking over their tiled surfaces with enormous curiosity.

"WHAT ARE THEY?"

"No clue."

The different segments appeared to rotate—Papyrus twisted them a little in his hands, eyes lighting up. "WHAT IS THE OBJECTIVE?"

Arbogast let out a little nervous huff of breath and somehow shrugged. "No clue. But I hope you enjoy finding it out!"

Sans had already pulled away from the two of them to go look for the resident intern; the only person—the only _normal_ person—who would spare time out of their busy schedule to talk to him. And really the only person who didn't treat him like he was the same age as Papyrus. They talked about normal things. …Or at least things that were less weird and childish than carrying around colored cubes in your mouth.

He remembered the first time that he'd seen her. She'd come crashing into the lab an hour late, huffing and out of breath with her glasses askew on her bright yellow face. It was probably a million times less disruptive than what she had to be imagining in her head, looking as though she was going to wring her hands right off. Gaster had—

Well he hadn't been furious exactly. He'd actually seemed…almost paternally concerned? But the way that she'd reacted-

"I-I-I'm sorry—" She had been trembling pretty badly, weakly trying to tuck her hands into her armpits for support. "I was up late last night looking over a—a thing I found at the dump and I over—"

"Does it have to do with your project, Alphys?" It might have sounded like a punishing rhetorical question but everyone knew enough by now to tell it was genuine. Alphys stammered so hard that her response wasn't entirely intelligible. Something about "inspiration for ideas". Gaster didn't look particularly impressed and cocked his head, the brow over his healthy eye flattening. "If the products of your little excursions are interfering with your work, perhaps it would be best to stop, yes?"

Sans had thought she might start crying right there and he'd felt—bad.

So he'd told a joke.

And Alphys hadn't laughed and Gaster had stared at him.

The "Royal Scientist" never laughed at any jokes, he didn't know why he'd spoken up. "I do not understand. That was not a word."

"no it—i made it up. it—" He had never, in his entire life, ever had to explain a pun before. But he did.

There was a beat. Alphys' cheeks had been remarkably red -she had to have been holding her breath. Then there was a spark of understanding in Gaster's eyes as the joke had clicked. He put a hand to his cheek, curling his fingers in his eyesocket somewhat and then laughed like it was the first pun he'd ever heard, smile stretched wide over his face.

…Actually, maybe it had been.

And Sans had grinned wider even as Papyrus slapped his back behind him, huffing, "YOU _ALWAYS_ TELL THAT ONE! NEW DAD DON'T ENCOURAGE HIM!"

So Sans added another one. The older skeleton's mirth halted and his eyes fixed on him for a moment while he processed the joke. Then he started laughing so hard that that it had suddenly switched to wingding.

…It was a nice memory and she always reminded him of it in her own way.

Alphys had thanked him profusely for that when everyone returned to their work. Like he'd saved her from some great humiliation instead of a light scolding. And that had made him laugh. He'd always thought adults were supposed to be put together and aloof. Maybe she wasn't as grown up as the rest of them.

That pattern of nervous behavior had continued, though lessened somewhat with him, at least. Today she seemed to be trying to melt into the machine she was working on, doing more leaning against it than the calibration corrections that she'd been tasked with yesterday. Glancing back, Papyrus seemed wholly distracted with the cubes that that Arbogast had brought, and Gaster certainly wasn't paying attention to them anymore.

"hey."

Alphys dropped the wrench that she had been half-heartedly using and Sans jumped at the clattering of metal on tile.

"Oh! –H—hey Sans." She made her little nervous, shaky grin and went to recollect her things. He shoved a hand in his pocket as he watched her scurry about, before pointing towards a piece that she'd been trying to jam into the workings of the machine.

"you got that backwards."

"What?" She looked to where his phalange was gesturing and blanched, going to carefully extract the piece and put it in the right way. "—Th-thanks. I guess I'm—I'm pretty tired today. I keep—making mistakes."

"were you up all night watching those human cartoons?"

Her face went beet red again and he guessed that it was correct. "They're just—so addicting, oh my gosh. I start one when I get home from work and then it's just—midnight. Then I'm too excited to sleep."

That makes him chuckle. "you know i think there's a nap for that."

Alphys snorted and gave him a look, before handing him a screwdriver. "…Thanks for—helping me out with the extractor, by the way."

"no problem."

Unprompted, she continued, as though embarrassed, "I think I did better earlier it's just—I've been at it for so long, I'm kind of bored of it already."

"that part over there is out of alignment." This time she smiled when she saw the error, and he could tell she was starting to relax a little bit.

"You know Sans—" It took a few more minor corrections before she'd fixed the mistake, and then Alphys pulled off another panel and began to sort through an incredibly convoluted and tangled mess of blue and red wires. "—You're really picking up a lot of this fast." When she smiled back at him all the confidence seemed to naturally drain out of her voice. "Um—I mean for—for a kid you know."

"yeah?"

"I was just thinking—well King Asgore wants as many minds working on this stuff as possible—and it's not like you don't have a direct line to the Royal Scientist himself—" It was fortunate for her that she turned away before she could see the slight displeased tint that entered Sans' expression at that. "—I think if you, you know, talked to him? You could probably work in here a little, like—like an intern, like me. We could uh—" By the time she looked back, that embarrassed little grin on her face, he was back to his usual look. Guarded but not actually looking guarded at all. "—We could be work buddies."

"eh." His eyes relaxed a little and he scuffed his shoes on the scraped linoleum floor. Not that it was an entirely unappealing concept in itself. "i don't know if I wanna make that a thing. it sounds like a lot of effort and…i already have to live with the guy, i'm not sure I wanna work with him too."

"But-!" Alphys' eyes widened somewhat behind her lenses, face flushing. "But he's the—the greatest mind in the underground! Maybe even among hu-humans too! I'd give my left lung to work with hi-here! –I mean I—I do work here, but…I'm a long way from being…a doctor."

He almost laughed and called her lame but instead he nudged another piece of the "extractor" into its correct place with the tip of his shoe.

"…I do understand though." When he looked up again her features had softened somewhat, and her gaze seemed intensely distracted. "I mean, he _is_ pretty intimidating. …After all, he's the one who, you know. Made the Core."

Alphys liked to bring that up. Apparently it was something she thought was particularly amazing.

"you sure do like garbage, huh?"

Something in her tone was quick and snapping. "—What?"

He pointed down at a dirty and rumpled cover of some comic book sticking out of her labcoat pocket. "…that's from the dump, isn't it? you go there a lot."

"…Oh. –Yeah, I do."

"that's weird." When she gave him a bit of a look he added quickly, "my bro and i used to go there when we didn't have anything and—we never got anything that was really worth much. just a bunch of junk. i didn't even know there were movies there that weren't busted up."

Alphys face seemed to light up—not necessarily from cheer but the sudden influx of _knowing something_ and being able to share that knowledge with someone else. "You just uh—you have to know what to look for! I know all the best dumping spots, where things are in good condition."

"yeah?" That sounded a little far-fetched considering how much digging through rotted fruit and half burned clothes the two brothers had to do when they were desperate, but then again—the dump was a pretty big place. And the water replaced the garbage almost daily.

"I have some…girls I tend to go there with. They're sort of like my little sisters I guess?-?. Maybe—you and your brother could come too some time?-?"

The offer genuinely surprised him, and he looked back in her direction as she returned to her work. Willing to talk or not—Alphys was an adult. …True, she was less of an adult than any other adult he'd met, but…he still saw her as such. Watching him while he kicked around the lab waiting for when he and Papyrus could leave and fighting off boredom was different than going on an actual outing together.

Granted, it was still to the dump. But-

"…yeah. yeah i think that'd be nice."

* * *

 **Author's Note** : I apologize for my slowness—college has gotten extremely busy and it's hard to find energy or time to write. I also have a tendency to juggle many personal projects at once—this isn't the only thing I'm doing. I do very much intend to finish this fic if I can, however—there's a lot I want to get to. It's just a little difficult to get there quickly.


	5. Arc II Chapter 2

Arc II: The Lab

Chapter II

* * *

"Some time" ended up being a few days later, over the weekend when Sans and Papyrus were alone at the house. One occupying himself with relaxing and pulling out the threads of a new sweater he'd been gifted at least a week ago, and the other trying to solve the "language puzzle" that was wingding, poised over a sheet of the symbols and occasionally muttering some of the nonsensical syllables to himself, scrawling down uppercase letters. The periods where Gaster left the two of them alone in the house to head to the lab were often filled with what felt to Sans like a relaxed and melancholy silence. Albeit in nicer living conditions, it was just the two of them on their own again.

Even if Papyrus had picked up their adoptive father's annoying habit of chewing on things while he was thinking. Crunched up pencils littered the floor around his desk.

There was a nice hole forming on the side of the sweater, fuzzy thread littering the couch on which he sat, when Sans heard a soft, timid knock on their door.

He almost considered not answering before sighing, sticking his right arm down to hide the hole, and heading over to open the door a crack with his left hand.

There stood Alphys, wearing a baggy sweater and some jeans-in sharp contrast to the labcoat she wore with disproportionate pride around the lab. She seemed startled to see him, which was odd considering this was his house.

"Oh! H-hey Sans!" He grinned at her, and the nervous air she spoke with diminished just a bit. "I happened to be in the neighborhood—well I mean really I was just passing through—and I thought—I thought maybe you'd like to come with me?.?"

"yeah?"

"Yeah—I mean uh—The-the offer I made the other day. I'm heading out to the dump in Waterfall and I'm on my way to see Bratty and Catty. …Are you two busy? Is Dr. Gas—ter here?"

Sans' smile almost dropped into a sneer at her last question. Maybe that's who she'd thought would answer the door. "nah. he's at the lab. papyrus is just working on his wingding and i'm killing time. we're not busy."

"OF COURSE WE'RE BUSY." Before he'd realized it, Papyrus had made his way up to his side, his little arms bent so that his hands were on his hips. "DAD TOLD US TO STAY HERE AND DO OUR STUDIES SO WE'RE DOING OUR STUDIES."

"—Oh!" Alphys gave a start when she noticed the younger skeleton standing there. "Oh no, I—I wasn't—I just thought maybe you could use a break?.?" As usual at a loss for words, shuffling awkwardly with her feet. "Sans was telling me about how you two used to go the dump so—"

"—THAT'S NICE GO AWAY ALPHYS WE'LL SEE YOU LATER." Papyrus put his small hands on the door and attempted to shove it closed.

Sans easily held it open. "'could you excuse us for a sec?" Alphys looked a little unsure for a moment but nodded, and he allowed the door to swing shut. With at least a little bit of privacy he then turned on his brother, beginning a "bro what gives?" before seeing the expression that was on his brother's face. It was one that he hadn't seen since Dr. Gaster had taken them in, one that choked up his speech and kept him silent.

Fear.

"YOU'RE GOING TO RUIN IT." Oh there was petulant, childish anger in there too, his brother's little fists shaking and teeth clenched hard enough that they almost rattled. But the fear was palpable and it made his heart ache. "HE'S GOING TO COME BACK AND SEE US NOT HERE AND GET MAD AND THEN WE WON'T HAVE A HOME ANYMORE."

"…papyrus…"

"I'VE BEEN TRYING REALLY _REALLY_ HARD." His cacophonic voice seemed to shake somewhat as he spoke, looking down at his feet. "AND I THINK HE LIKES US, BUT—HE TOLD US TO STAY HOME AND I DON'T WANNA—I DON'T WANT HIM TO-."

"hey, hey bro it's okay," Sans stepped over and pulled Papyrus into his arms, his little brother shaking slightly. "it's okay. we're just gonna go out for a little bit, alright? he's not even gonna notice we're gone. you know how late he comes home."

"WHAT DO YOU EVEN WANT TO GO TO THE DUMP FOR?" Papyrus made a dry sniffle, not moving to return the hug but the tension slightly leaving his shoulders. "WE ALREADY HAVE LOTS OF NICE THINGS HERE."

"yeah but he's not really the most creative with them, is he? i mean bro, we're wearing monochrome stripes half the time." Patting his brother on the back, Sans looked down at his shirt and added, "i was just thinking we could head down there and—and get something nice. it's not the end of the world. besides, aren't you always saying it's our job to liven things up a little bit? –it'll be fun."

Sans was unable to describe to his sibling just how little fun he'd been having since they moved in. How suffocating it was to stay in the house with no toys or games or drop by the lab where there was nothing but work and he was constantly scolded if he touched anything. A dump was a dump, sure—but it was closer to a playground than anything else they had. He tried to put this into his tone. Tried to let him know somehow.

"—and even if _you_ don't wanna go, i am."

" _NO!_ " Papyrus was aghast at that, running over to grab his coat. "NO YOU'RE NOT GOING WITHOUT ME I'M COMING TOO." He swung the door open to see Alphys still standing there, looking as though she'd just had her ear pressed up against the wood. "ALPHYS I'M COMING TOO."

"O-oh!" She grinned sheepishly and straightened up, smoothing down her shirt a little bit. "That's great! Uh—great! Let's go, then."

* * *

Bratty and Catty turned out to be a thin young crocodile monster in yellow braids, and a slightly rotund cat monster with a black bob cut, respectively. The two of them looked almost around Sans' age, although it was hard to tell, the way they spoke and carried themselves. They also didn't wear stripes.

Despite being roughly the same height as the two skeletons, they cooed over them just like two newly mothered women when they saw them.

"Alphys oh-em-gee! Where did you find them they are _so_ adorable!" It was hard to tell what they were saying at first—Both of them tended to speak at the same time, and while the basic sentiments were the same the wording differed slightly between them.

Alphys gave a nervous chuckle and put her hands on the boys' shoulders—then she took her hand off Sans when he glanced at her. "These a-are Gaster's new kids? The uh—the ones he adopted."

"You two are _so_ lucky!—

"Yeah, I bet he's all like, distracted all the time with science-y stuff—

"You can totally sneak out whenever you want, I bet—switch the sugar out with salt or something.

"…EL-OH-EL."

Sans' smile grew a bit more genuine as he heard the mixing sounds of the girls' mutual laughter and Papyrus' sputtered indignation.

The dump wasn't too far from Hotland—down in Waterfall. About an hour's walk if they were going by foot, but unlike their resident Royal Scientist none of them had any issue with using the Riverperson to get from place to place. It was almost amusing trying to get everyone crammed onto the little boat….creature.

As it ran across the water's surface Sans started to think maybe Gaster had a point.

The perilous part of the journey over, it was practically a hop skip and a jump to the dump, the girls chatting as they walked and Papyrus making sure that Sans was holding his hand so that he didn't wander off and get lost like he tended to do sometimes. It had been a while since they were in Waterfall—the community was smaller and it was harder to get by stealing food when everyone could remember your face. Not to mention the damp chill made it hard to sleep.

It felt oddly nostalgic to be back.

"Here we are!" Alphys stopped them at the entrance to the dumps cavern, one of her patented shaky smiles on her face. The area was just as piled high with garbage as the last time they'd been there, although it was quite a bit more flooded than the brothers remembered, an old milk carton floating by as they stood at the edge of the water. Bratty immediately strode in, laughing and splashing, while Catty lingered with her fur on end.

"Bratty you should totally bring me a raft."

Sans put his arms around Papyrus' waist and carefully hoisted him up on his shoulders as he slipped off his shoes. The water wasn't particularly deep—only about knee height. But he didn't want anything they were wearing to get wet, and his brother was short enough that his pant-legs were sure to get soaked. And it wasn't like they had thighs to roll them up on.

He glanced back at Alphys before wading in. "you mentioned something about finding the best spots?"

To his mild surprise, she was actually backing away down the path they'd come from, a rosy blush in her cheeks. "Actually—a-actually there's—someone I was thinking of talking to w-while we're in the area. –I-it's no one important!" she hastily added at the questioning look. "I won't be gone too long, just gonna—drop in and say hi. …Yeah…gonna—drop in and say hi. I'll be back to show you around soon, I promise."

Not holding out too much hope for that considering how long it would probably take for her to work up the courage to open the door, the way she was shaking and sweating, Sans kept his hands on his brother's shins as Papyrus's arms wrapped around the top of his skull, and the two of them made their way down into the water.

"euuugh."

"WHAT?" Papyrus' voice was almost painful so close to his head, but Sans' smile never wavered for a second.

"well bro i don't wanna talk _trash_ about this place—"

"LET ME DOWN I'LL GO LOOKING FOR STUFF ON MY OWN."

His brother swayed on his back and Sans laughed, holding onto Papyrus' legs a bit more tightly to keep him from falling off. "if you keep making fun of my jokes i might end up down in the _dumps."_

"LET ME DOWN, LET ME DOWN."

He was laughing, though. Pretending to strike Sans on the top of his head with his little fists and laughing.

It didn't even really matter if they found anything worthwhile out here. Let Alphys go talk to whoever she wanted. He was having fun right here. This was all he needed.

They were so busy enjoying themselves that they didn't realize how far away they had gotten from the entrance to the dumping grounds.

It wasn't a particularly large place—the entire room could be traversed in a couple of minutes at most. But the shifting piles of garbage being swept away and rearranged in the current made it a little hard to keep track of yourself. Not to mention the overall darkness that permeated Waterfall more than any other area of the underground, pushed back against only by the eerie glow of light traveling through and reflecting up from the water that swallowed Sans' shins.

He wasn't too worried, idling by a rather stubborn trash pile and looking it over. This one had a lot of crushed juice cartons, candy wrappers, and ink cartridges. He picked one up, letting the black smudge over his finger bones, before Papyrus made a soft sound and tapped on his head.

"DON'T BE RUDE SANS."

"…huh?"

Papyrus tapped his forehead again and pointed to the side, and Sans glanced in the direction he indicated. Standing in front of them about a few feet away, some CDs in his mouth, was a light orange, armless monster with a yellow-striped shirt and spikes going down his back.

He stared at them, eyes wide as dinner plates.

"…hey there."

No response. …Possibly because his mouth was occupied. Sans took a step forward.

"Are you here with anybo—"

And then the pair almost toppled over as he suddenly dashed past them, feet splashing and soaking their clothes with grimy water. Papyrus let out a bloodcurdling screech and for a moment Sans thought he had gone completely deaf.

"NOW HE'LL KNOW." Before he could stop him Papyrus wobbled off his back, getting his shirt in even worse shape as he hit the water. "WE RUINED THE NICE CLOTHES HE GOT FOR US."

"they're not ruined." Sans pulled Papyrus in and started uselessly scraping his fingers against his shirt, as though trying to get the trash off. "they're just a little soggy is all, hold on—we can just dry off when we get out of here, we can pass through hotland—"

"SANS YOU'RE NOT HELPING STOP." Splashing even more in the water, the smaller skeleton pulled away, arms waving his brother off. "IT'S TOO LATE."

"…sorry paps. –caught me off guard."

"WELL…" The panic on his face slowly melted off, looking around them a little bit more inquisitively."…I GUESS NOW THAT WE'RE ALREADY A MESS—WE CAN GO ROOTING AROUND IN THE GARBAGE NOW?"

Sans blinked. Then he started to laugh. "yeah. sure, go for it bro."

Papyrus jumped for one of the taller trash piles, carefully sifting through it for anything still usable—something that wasn't covered in sludge or ruined by the water. Sans went for a neighboring pile, although he was never really all that good at looking. It felt like too much work or too little payoff. But he didn't mind watching his brother work.

Again it felt a little bit like back when it was just the two of them, for a moment. …Sure, they hadn't had much. But they'd had each other. They could do whatever they wanted without needing anyone's permission and no one ever forced them to stay in separate rooms.

"SANS?"

He snapped from his thoughts, elbow sinking into a moldy piece of bread, when his brother waved a rolled up poster in his face. That was fast. "huh?"

"SANS PAY ATTENTION." He fiddled with the poster—it was continually curling as he tried to unravel it, eventually revealing a large image of a skull surrounded by flames "DO YOU THINK HE WOULD LIKE THIS? DO YOU THINK HE WOULD LET ME HANG THIS UP IN THE LIVING ROOM?"

"do i _what_?"

"I THINK IT WOULD ADD SOME COLOR. –AND IT LOOKS COOL, RIGHT? IT'S ONLY A LITTLE BIT TORN." Papyrus waved the picture around a little bit, the upper right corner flapping. "DO YOU THINK HE'LL LET ME?"

"i dunno bro, that's pretty orange. i think his style is more monochrome."

He decided he didn't like the way Papyrus' eyes tilted in disappointment, and started to open his mouth to amend the statement. That's when he noticed the splashing of two other figures making their way over to join them.

"Oh-em-gee, sweet poster, little guy!" Bratty was wading through the water, clothes clinging to her thin form. It was clear she had actually been swimming around in the garbage water and the thought of that almost made Sans chuckle. When he saw Catty hopping among the piles as though terrified of getting even a single splash on her fur, the noise finally came out. He rested his bony hands on his hips and Papyrus started rolling the poster back up, looking vaguely affronted. Probably from being called "little guy".

"you two don't have any loot?"

"We like to wait for Alphys. She's good at picking out things that aren't gross. Like CDs and makeup and guns and stuff."

"yeah?" Papyrus had started stubbornly going through the pile again once he had the poster securely tucked under his arm—a few cans fell out and floated away. "she still not back yet? she said she'd help us out too."

Catty laughed, putting a paw to her mouth. "She's probably trying to go talk to her cruuuush~"

Bratty slapped her claws on either side of her long face. "Oh my god, she must be."

That piqued Sans' interest, and the water sloshed a little as he took a step towards the ill-matching pair. "crush? this is the first time i've heard about that. …or… i didn't think her crush lived anywhere near here."

The two girls giggled together. "It's probably a different person."

"Yeah Alphys has a few crushes."

" _really_?"

"Apparently one of the times she was here alone—"

"She met this cute fish."

"So whenever she takes us out here she goes to visit her—stare at her house." The two of them started laughing.

Sans actually started to laugh too. "what, really? that's what she's doin' right now?"

Papyrus looked up from where he was tossing moldy socks back to be carried away by the stream. "WHY WOULD SHE WANT TO STARE AT SOMEBODY'S HOUSE?"

"Well she really wants to go knock on the door—"

"—But she doesn't have the nerve." Catty made a face and peeled a banana skin from the underside of her foot. "I'm sure she'll be back in a minute, it doesn't take her too long to give up."

"Gosh someone needs to give her a push. It's kind of sad actually, she gets so disappointed that she can't work up the nerve to see her again."

"oh, don't worry. I'll be sure to give her some _ribbing_ over it tomorrow. maybe that'll be the push she needs."

"STOP." A damp washcloth hit the side of his face, and he glanced back at Papyrus, who was now waist deep in various articles of garbage with his hands on his hips. "STOP GOSSIPING IT'S NOT NICE."

"don't—" If skeletons could blanche, Sans likely would have at that point. "—don't call it gossiping."

"WELL THAT'S WHAT YOU'RE DOING."

Catty laughed, and the crease on Papyrus' brow deepened. "Aw the little tyke is right, we should probably focus more on finding some cool stuff."

"—That reminds me!" Sans only just noticed a pair of sleeves tied around Bratty's waist as she carefully undid the knot, handing the jacket they were attached to Sans. "I noticed you didn't have a coat, and I know Waterfall gets kinda cold. –It's not like me and Catty need it."

"We could hear your bones rattling the whole way here!" the cat chortled.

To be more accurate, as Sans turned it over in his hands, the article in question was a hoodie. Zippered up, a little stretched. He didn't have time to give them a thank you, or really respond at all—the group turned to hear splashing as a certain yellow monster hauled her slightly chubby frame through the water to greet them.

It was a nice gesture. His smile became just a little smaller, more to relax his face than anything else. It was a nice gesture but the article of clothing was soggy, stained, and smelled absolutely terrible. He didn't know how to explain it when they got back or what contexts he'd be allowed to wear it in.

And that was sort of the problem wasn't it?

As Alphys apologized profusely for her absence and Papyrus ran out to her to get a second opinion on his poster, Sans quietly tossed the hoodie back into the junk pile.

Red wasn't really his color anyway.


	6. Arc II Chapter 3

Arc II: The Lab

Chapter III

* * *

"He can't."

"he can."

"No way."

Papyrus tried to ignore the voices behind him, teeth grinding together somewhat as he clenched his jaw in concentration. He had a bone attack forming in his hand, although it wasn't quite ready yet. –Sans could conjure them up fairly effortlessly but it would take a little bit more practice before the younger brother was ready for such a feat.

"his aim is pretty good."

"Shut _up_."

"scout's honor."

"YOU ARE SABOTAGING ME," Papyrus wailed, stomping his foot into the water and making a hefty splash. –If the armless monster hadn't ruined his clothes before, they were well and truly hopeless by now.

"sorry." Sans grinned wider and gave him a thumb's up, standing in between the pair of Bratty and Catty, and Alphys. He noticed that he wasn't wearing the hoodie that Bratty had given him, but he didn't wear anything over his T-shirts after Gaster had thrown out his coat. So it was only natural, even if he was clearly shivering a little.

Staring at them for a moment to make sure they didn't chat anymore, Papyrus turned around and finished preparing his bone attack, feeling the weight of his magic in the air. With a small cry he fired the array of projectiles at a rigged up target range—several slightly cracked bottles evenly spaced on hastily piled garbage. To his severe delight—and the clapping of his audience—all but two hit their target, scattering glass and leftover whiskey in the water.

"HA!" He turned around to point at Catty, triumph written all over his face. "I DID BETTER THAN YOU DID!"

"Yeah, by like _one_ bottle."

Bratty chuckled beside her friend before easily cutting through the water to set up another set. Papyrus watched her for a moment before turning to his brother. "IT'S YOUR TURN SANS."

"nnnnaaah. i'd probably miss all of 'em. –how about you go again for me?"

"SANS THAT RUINS THE WHOLE POINT OF THE EXERCISE." He stomped his foot again, splashing and firing another small bone attack to loop through the air before dissipating. "YOU'RE REALLY GOOD AT MAGIC I KNOW YOU CAN DO IT!"

"so you already know what i can do." Sans shrugged, rolling on his heels and taking a few steps towards him.

"BUT _THEY_ DON'T."

Papyrus folded his arms as Sans started patting him on the head, a lazy grin on his face. "you're the only person i care about impressing, bro."

Before he could protest that incredibly transparent excuse, Bratty and Catty stepped in with an "Awww. That's okay—we still haven't seen anything from Alphys."

"Yeah she should totally knock over the next batch."

"We never see anything from you, Alphy."

At that, Alphys' face went beet red as all eyes turned to her, fumbling around with her fingers. "Oh. W-well I, uh—I can't really do…most magic?.?"

Well that didn't sound right.

She waited a little bit, as though that should explain everything, before realizing that everyone was expecting clarification. "I mean I'm—I'm only good at things that involve technology. Magic technology? Uh…" To stall for time she cleared her throat, "I don't really do the—projectile stuff? Myself?.?.?"

Catty nudged her, smiling. "Aw come on, Alphy. I'm sure you could if you tried.

Alphys shook a little bit, grinning crookedly, before she suddenly turned her head towards the skeleton brothers, cheeks red. "Well didn't—didn't you two uh, have something to do with blue magic too?" It was clear she was trying to change the subject. It was a bad change in subject. She might not have seen the way Sans' eyes almost went out for a moment but Papyrus did. "How about you—how about you show us that?"

There was silence for a moment as everyone instead turned to the them. Papyrus heard Sans suck in some air to start speaking, but he interjected first, "SURE, I CAN GIVE IT A TRY."

He had never used blue magic before, but…

"nah papyrus you don't have to do that, it's fine. –it's a little hard."

Papyrus merely scowled and rolled up his sleeves, turning around towards the two remaining bottles and stomping over.

"bro?"

"BOTTLES!" Papyrus pointed in their direction with two fingers in a "v", talking like the hero in the comic book Alphys had picked out earlier while he tried to figure out how to summon blue magic. "PREPARE TO MEET YOUR MATCH!"

"Oh my _god_."

They'd only spoken about the ability once before. Back when Sans had first used it to defend them against some bullies in the capital. His description hadn't been very helpful-saying it was emotionally driven, a force that had risen up within him when he'd gotten…angry or scared…but then sometimes it was also something that came up when he was practicing, and in those instances he was calm and focused. …So that didn't really help Papyrus at all. But he did know, for sure, that it involved augmenting existing attacks, like the bone attacks that both of them could do. So he brought one forth, looking down at it in his hand as though willing it to turn blue.

It did not.

Sans placed his hand on his shoulder, voice a little quiet so the others wouldn't hear, "listen paps maybe this is something we should practice on our own first before you start showing off for—"

"NO NO." Papyrus pushed him away, feeling a nervous prickling in his spine. "I CAN DO THIS, I CAN. I JUST GOTTA—DO IT."

"do you even know how to—"

"OF COURSE I DO!" He waved his hand to demonstrate and a normal bone attack went whizzing by one of the whiskey bottles. The younger skeleton could feel his shoulders start to waver, conjuring another attack to try. "I JUST—I JUST—"

If it was within himself, he didn't know how to reach it. The nervous prickling got worse, and he felt like screaming. But then everyone would stare at him even worse than they were doing now. He turned to look at them—heads tilted quizzically, Alphys looking uncertain but then she always did. They were going to laugh at him. They would think he was so stupid, that he couldn't do anything-

Sans' hand twitched.

The bone attack that Papyrus had summoned went a brilliant shade of blue.

"-AH!?"

In his surprise, he dropped the attack and it harmlessly fell into the water, not even making a splash. All of them stared at the spot, Papyrus a little bug-eyed, before he suddenly jumped up and pointed directly at his brother. "HAH!"

"eh?"

" _I TOLD YOU I COULD DO IT!"_ He turned to the others, who were now all smiling, taking steps forward to pat him on the shoulder and congratulate him. "YOU SAW THAT RIGHT, I DID IT?"

"That was really impressive." Alphys was giving Sans a look that Papyrus didn't understand, but he didn't care, preening a little bit under the praise. "Especially so young—with a bit of practice that'll definitely come in handy."

Sans winked. "bottles beware, am i right bro?"

"BOTTLES BEWARE!" Papyrus nodded and he listened to Bratty and Catty giggle. "OH WAIT—THE BLUE ATTACKS ONLY HIT THINGS THAT ARE MOVING? …DO BOTTLES MOVE?"

"They do if you throw them like shot put." Catty cackled a little bit, springing over the piles to grab one of the set up bottles. "We'll save these for later then. –The light shines through them kind of nice actually—Hey Alphy can we keep these?"

"Uh, sure, sure. –Just don't, um, break them? Because glass is uh—dangerous. Broken."

"Kaaay!" They took a bottle each. "We'll get something else for you to hit, little guy."

"Something we can throw in the air."

"And isn't filled with weird human drinks."

As the two were chattering on Papyrus leaned over to speak to Sans, voice low. "UM, SANS?"

"yeah?"

"WHAT IS A 'SHOT PUT'?"

"uh…"

Papyrus had been unable to replicate the attack for the rest of the visit to the dump. But that was alright. Because he and Sans were having fun with people who liked them. And that was something sorely missing from their lives, both before and after being adopted.

And besides, now he knew he could do it. And with a little bit of practice (probably with Sans, if he could ever get him to make the effort), he knew he could do it again.

* * *

After dropping off Bratty and Catty with the riverperson, Alphys accompanied the boys the long way back home. They still needed to dry off, after all—at least then the miserable state of their clothes wouldn't be too noticeable, at least until they were able to change into something cleaner. Papyrus kicking around the place as his two elders trudged along, waving his poster at the last few echo flowers they passed.

"…I'm sorry you didn't get anything."

The wind slowly started to drop and the air became less damp as they walked, Sans' hands in his pants pockets and his gaze carefully keeping track of his footsteps. When he heard her speak, he glanced back up, perma-grin shifting in mild confusion. "eh? nah, that's fine. i saw some nice stuff, had a good time—that's enough for me."

"Yeah? …Okay. –I'm glad Papyrus likes what he got?.? Maybe I can find a comic for him next time I drop by here, I think he'd like that."

"i'm sure he would."

Truth be told he didn't mind the silence. He more minded how the "stars" on the ceiling fell away as they passed the scrolling sign welcoming them to Hotland. But it was good to get his thoughts in order, rolling around the day's events in his head. Even if Alphys occasionally cleared her throat as though she intended to say something but was chickening out.

Eventually though he took mercy on her and brought another conversation starter into mind.

"hey uh…just out of curiosity, have you ever seen other people there at the dump when you're going? like…a kid with no arms?"

"A kid with no _arms_?.?" Alphys gawped a little before shaking her head. "You mean like…one of the ghost monsters?"

"nah. more like…a kid with no arms."

"HE SPLASHED US." Papyrus glanced back from where he was up at the front, wagging the poster as though scolding the child who was not present. "RIGHT AFTER WE SAID HELLO! IT WASN'T VERY NICE!"

Alphys looked between the two of them a little uncertainly. "…Right. –Well—lots of people like to use the dump? …Probably just one of the locals?.?"

"yeah…i guess. –seemed a little shy, that's all." The conversation lulled again as they all carefully made their way over the footbridge into town. Thinking on that topic again afterwards reminded him of the "gossip" that he'd heard from Bratty and Catty just as they'd arrived, and he started chuckling to himself.

"…What?" It always seemed to make Alphys nervous when people laughed and she didn't know the cause, the glow from the magma throwing reddish light onto the crease in her brow. "—What's so funny?"

"oh nothing. –i'll tell you tomorrow."

The elevators that Dr. George had been installing for bypassing the ludicrously complicated system of puzzles and layers that made up Hotland's streets were not completed, but they did thankfully shave off about twenty minutes of the trip. Not to mention it meant they didn't have to pass through the lab and risk getting caught.

Some light music played as they stood in the room. It reminded Sans of his first day in the lab. …He was pleased to say that they didn't scare him as much as they did then, especially now that he understood how they worked.

"ALPHYS CAN WE GO TO THE DUMP WITH YOU AGAIN?" Papyrus lightly whapped her with the poster and she jumped, smiling a little despite herself and adjusting her glasses. "…I HAVE TO SHOW THEM MY BLUE ATTACK WHEN I CAN DO IT BETTER."

"Sure—sure, well—I would have to check with—with Bratty and Catty but we can also go just the three of us too? Uh—when we're all not busy, I mean…"

Sans chuckled, going to take Papyrus' poster from him so he could unroll it and look again at the contents. "the little boy scout wants to sneak out more? careful pap, i might end up being proud of you."

"WELL—" Flustered, his brother stomped his boot and started fumbling to reclaim his poster. Sans easily held him back. "MAYBE WE COULD ASK NEXT TIME?"

There was a small _ding!_ and the doors slid open. Alphys seemed to avoid the comment, hustling the both of them out and going quiet.

The pleasant heat that permeated the air slowly became more unbearable as their chilly, water soaked clothes began to dry. They tried to hurry the rest of the way—stopping twice for water, the first time to refresh themselves and the second time to put out Papyrus' poster when it caught on fire. There was little discussion during this period, although after the last stop Papyrus spent a few minutes half-crying to himself (even though only two corners were singed).

As they got back into the capital it was clear a lot of time had passed—more than Sans had thought they would spend on their outing. The street lights were dimmer, and it was just the tiniest bit harder to find the house.

"I guess we'll see you again at work tomorrow?"

"Yeah. –Y-yeah and hopefully I won't show up late." Alphys made a little nervous laugh, looking down at a couple DVD cases that she had clutched in her claws. "I'll probably watch these all night, but…"

"what even are those things? some kind of human cartoon?" He reached out a hand to take one of the cases from her but she jealously held them back. That made him chuckle. "some super special human cartoon?"

"It's-it's just this really brilliant—well made thing. This one's—this one has living machines in it, I think it's the prequel to the one that I was watching last week?.?.? Because the main character is in it but his hair is shorter and he looks a little younger, so I think it might be about how he and the X-One unit met?.? But it's just—this really in-depth story about what it means to be human and all that stuff which of course it would be human centric because humans made it but anyway there's some cool transformation sequences for the X-series that I wanted to try making because—"

Sans' eyes were still on Alphys when she stopped walking and talking, pupils shrinking and mouth dropping open in a small expression of horror—so he didn't immediately know what had alarmed her like that. At first he'd assumed that maybe she'd said something she wasn't supposed to, like one of those "spoilers" that she was always so careful of. But then he glanced in the direction she was looking and understood.

Dr. Gaster was waiting for them in front of their house, holed hands resting on his forearms and back leaning against the wood of the door. Though his right eye couldn't express much, it was clear—from his left eye—how displeased he was when they came into view.

Sans felt Papyrus grab his hand from beside him and grip it painfully tight.

"…Having fun?"

* * *

 **Author Note:** Ahhh, thank you all so much for the kind reviews! I didn't realize I was going to get such a positive reception, but I'm so glad I have! I've still been having some minor writer's block issues for the next couple of chapters but I've definitely been writing and planning more for later in the fic, which I hope makes up for it at least a little.

 **edit:** Also-I don't want to spoil anything but yes there is going to be some...Unpleasantness up ahead.


	7. Arc II Chapter 4

Arc II: The Lab

Chapter IV

* * *

How **_dare_** they?

The moment Gaster had put his hand on the door and found it unlocked he'd felt a strange kind of anxiety in his chest. Confusion and worry worming their way into his mind. The feelings had only been compounded when he didn't see the children where he'd left them, didn't hear them respond when he called their names. Where were they? Had someone gotten into the house? Or worse, had they run off? Not knowing something had never caused him so much stress before, and he didn't know how to handle it. He almost tore up the building looking for them.

Then he'd found a very crudely written note atop the desk he'd set out for Papyrus to work on.

 _W E WENT OWT WITH ALFIS B BACK SOON_

And then all of the worry collecting inside him transformed into rage.

When he had left for Hotland that morning he had left _very_ clear instructions for what he expected them to do that day. Nowhere in those instructions had he given permission to go on an outing with his intern. His _irresponsible_ , _dumpster diving_ intern.

Now, his fingers tapped along his arms, eyes narrowed and firmly set on the three _children_ squirming nervously before him. Or rather the two children squirming and _Sans_ who was stock still with his eyelights out. He had only just gotten home—there hadn't been enough time for the anger to pass and the rational part of his mind to start determining a punishment.

"You can all _start_ —" He waved a finger between them threateningly, gritting his teeth slightly. "—by telling me where you two went and what is wrong with your clothes."

The three of them didn't immediately respond, glancing between each other. Briefly brushing his thumb over his cheekbone towards the crack in his eye, Gaster leaned down to focus on Papyrus. "Have I asked a difficult question?"

"WE WERE—UM—" The boy looked over at Sans, as though looking for approval, but his brother merely grinned and said nothing. "WE WERE WITH ALPHYS AT THE DUMP…"

"The _dump?_ " His eyes flashed at that—not sure if he should consider it a "learning expedition" like she always tried to paint it or just become even more frustrated. "Well that would _explain_ why you smell like _garbage_."

Sans coughed and it sounded like he was covering up a laugh. Gaster directed his gaze towards him and felt some measure of satisfaction at how quickly the smile drooped on his face. "Did I say you two could go to the dump? Is that what I told you to do? Clearly there has been some _confusion_. Tell me, Sans, tell me what I asked you two to do."

"…work on learning wingding."

"Very _good_ , you _are_ capable of listening." Of course, Gaster was capable of smiling too, the crease in his brow making it look a fair bit more cruel. "Say something to me in wingding, Sans."

Instead of doing as he was asked—because of course he wasn't able to—Sans murmured, scuffing his feet, "…to be fair, you didn't say we could… _not_ go to the dump."

Before he could object to that—as if he wouldn't be angry at them on a _technicality_ -Alphys stepped forward, attempting to raise her wavering voice. "D—Dr. Gaster it—it's not really their fault, I-I—"

He shot a stern look at her and from the way her expression changed one would think he'd just stabbed her. "I will deal with _you_ , later."

"-Y…yes sir…"

"I think for now you should go home, don't you think?"

"Yes—I—" She looked between the two brothers, eyes practically crescents beneath her glasses and feet stumbling to move away before the rest of her body could catch up. "I'll see you two later, um. Bye."

"BYE ALPHYS." Papyrus' voice was lower than usual, even if he was still shouting. "WE'LL SEE YOU TOMORROW."

"That is up for debate. Come along." He put his hands on the collars of their T-shirts and easily dragged them both inside the house, out of view of their friend. Sans pulled away with much more energy than his brother when Gaster let go to close the door, straightening out his clothes and frowning.

-What right did _he_ have to be angry?

"we didn't do anything wrong."

"You didn't do anything _wrong_?" The tone of incredulity was hard to mask, watching Papyrus sidle up to be just behind his brother, who stood as though prepared to fight him. "You don't think that sneaking out after I told you to work on your studies without even leaving a message letting me know where you _were_ counts as doing anything wr—what do you have there in your hands?"

He'd finally noticed a rolled up poster gripped in Papyrus' small fingers—tightly enough to put creases in the material. Without really waiting for a response, he reached over and snatched it from him, unrolling it and pausing to blink at the singed flaming skull design it was printed with. After a moment he looked over the top at them.

"What is this?"

They both glanced at each other without answering him initially—a gesture he was growing very very tired of at this point. But soon Papyrus stepped forward, wringing his fingers together and only half looking up.

"DO—DO YOU LIKE IT?"

"Do I _what_?" Truthfully it wasn't really all that bad. Fairly intricate linework, interesting flame patterns—even if it wasn't the kind of thing he would personally keep around the house. But the question seemed like a non sequitur. Although granted—it's not like he needed to be _told_ that what he was holding in his hands was a poster, deciding he'd seen enough and beginning to roll it up again.

"THAT'S—THAT'S WHY WE LEFT, WE WANTED TO HELP YOU DECORATE A LITTLE BIT, AND SANS DIDN'T GET ANYTHING BUT I FOUND THAT AND I THOUGHT YOU WOULD LIKE IT OR LET ME PUT IT UP IN MY ROOM OR—" The growing string of babble cut off at another look.

"[You two worried me _over a poster?_ ]"

He had never been before such an odd mix of flabbergasted and angry, reverting back to wingding to mutter to himself and strongly, strongly resisting the urge to whap them over the heads.

"WE WEREN'T TRYING TO WORRY YOU."

That stalled him.

…Had he been understood? –Certainly not by Sans, who was looking at his little brother with the same amount of bewilderment. Gaster frowned down at him in confusion, switching back to aster. "…Be that as it may, the fact is that you did."

"WE DIDN'T THINK YOU WOULD BE HOME…"

"it's not pap's fault, i told him you wouldn't be home before we got back." Sans stepped forward again, arms crossed uncomfortably over his front. "so…it's my fault."

Gaster merely waved him off, although the anger was starting to seep out of him. "You are both at fault. Don't talk as though your brother can't make his own decisions."

As though to hammer that point home, Papyrus opened his mouth to speak—Sans cut him off. "-it's not like you ever really spend any time with us anyway. you're always doing other things."

Again another reason to pause, because it was…true.

Naked attempt to change the subject though it was.

When did children become so astute?

Gaster sighed. "To be honest I didn't think that bothered you. You don't seem to like it when I'm around." The comment was directed at Sans in particular, although perhaps he should have specified because Papyrus then proceeded to vigorously shake his head. Before either of them could protest or make more excuses for themselves, he interjected with, "Perhaps I have not been giving this the attention that I should."

They both looked a little bit surprised at that. Which meant that they believed in his sincerity.

Not that he intended to be…insincere.

"I will…put more effort into being there for the two of you. I realize it is not fair to leave such…exceptional children to their own devices without anything to really amuse themselves with."

"wow."

He held his teeth together and handed the rolled up poster back to Papyrus, murmuring for his benefit, "[You may put that up in your room.]" The child seemed confused for a moment at that, frowning—but the intent of the sentence appeared to have gotten across when a smile broke out on him again. "Perhaps we can start by going to a proper store and getting some things you might actually enjoy. Whatever you want."

"REALLY?"

"—But for now, the two of you are grounded. And those shirts are going into an incinerator."

* * *

Because they were grounded, the next day they were once again left alone in the house while Gaster went to work. This time though he promised to come back on time instead of working late into the night on whatever project it was that he got so excited about.

Sans wasn't holding out hope on that one. But then he didn't really do that for anything.

Papyrus told him that now was a good chance to make up for their disobedience by actually studying, which Sans didn't really want to do either. So he puttered around the house a little, occasionally coming back just to drive his brother up the wall—break the pattern of concentration and hopefully save a few erasers from being mangled in the process.

It wasn't _bad_ here.

They'd been told that if they walked even one step outside the confines of the house, Gaster'd know about it and do something "terrible" to them. The minute he'd been out of sight at the window Sans had opened the door and pretended to walk outside. Papyrus had shrieked, and it had all been very fun and entertaining….but he didn't think he could actually take that step. And that bothered him. He didn't _think_ he was afraid. But he still felt better the minute the door was closed again.

He was inside Papyrus' room, attempting to put up the poster on his own despite being short and some of the singed edges crumbling under his touch, when he heard the front door open again. Sparing a glance to the clock he realized that Gaster was indeed on time to get home.

Coming down the stairs he overheard Papyrus say, "—BUT PROMISE YOU WON'T BE TOO MAD AT HIM BECAUSE IT'S NOT HIS FAULT."

"woooah paps are you selling me out or something?"

Both of them glanced his way, his younger brother beginning to break out in a sweat and wringing the hem of his shirt. "NO NO! I WAS TELLING HIM TO _NOT_ BE MAD AT YOU!"

Sans would have followed that up with a crack—maybe a joke about weasels or snitches or something—when he caught sight of the state of their returning caretaker, covered in ash and bone bruises. As he started to unbutton the coat he'd walked in with, more damage was visible underneath.

"uh, what happened to you?"

Gaster shrugged as he was hanging up his coat, a slight sanctimoniousness to his tone. "Well you would know that if you weren't grounded, wouldn't you?"

Maybe the two of them would be always side-stepping each other.

"–Speaking of which-" He then quickly switched to something more like a school-teacher would use, looking over the two of them with half-lidded eyes. Or, half-lidded _eye_ , as one of them was always partly closed. "Have you done the study work I told you to do?"

"I DID!" Papyrus looked like he was about to actually run to his desk to show him the worksheet but thankfully he didn't. "I LEARNED A LOT TODAY! ALTHOUGH I STILL CAN'T SAY ANY OF IT…"

Laughing and patting him on the head, Gaster murmured, "That is alright. Quite honestly I would be surprised if you were able to at this point. But we'll follow up on that later, hm? …What about you, Sans?" He added something—but it was completely unintelligible. Probably a test of some kind.

"no, i did not."

"No? Ah well. I have something else I wanted to talk to you about today anyway. –May I ask why not?"

That surprised him a little. Both the question and the fact that he wasn't being reprimanded. "uh—i didn't—feel like it?"

"Why didn't you?"

He suddenly felt helpless to explain himself, glancing at Papyrus. "I just…don't like doing stuff. Sometimes it's really hard." He didn't specify that he didn't like doing things _assigned_ to him in particular.

"SANS IS JUST LIKE THAT." Sometimes it was worse when they had a bad day, or week. Especially if they had nowhere to go. "HE'S ALWAYS BEEN LAZY."

"not _always."_

"Well, maybe there is something wrong with you."

They both stared.

"Physically, I mean." Gaster was preoccupying himself with some kind of jelly-like substance that wouldn't come off of his arm. "I could look into it. I believe Dr. Likker does some specializations in monster physiology, though granted he's never had skeletons to work with. …Why are you looking at me like that?"

"NO, SANS IS JUST—I MEAN HE CAN STILL DO THINGS? IT'S JUST THAT HE DOESN'T LIKE TO IF HE DOESN'T HAVE TO?" Papyrus seemed a bit more taken aback by it than Sans himself, wringing his shirt again while Sans merely shoved his hands in his pockets.

"Perhaps there is something wrong with him _psychologically_ then." Clearly disinterested in pursuing that line of inquiry he started fumbling around in the pockets of the coat he'd just hung up. "In any case, Dr. Arbogast did bring something for you today, Papyrus. And since you have been so good and so dedicated recently I thought it might be a suitable reward."

"—REALLY?.?" All other thoughts were pushed out of the boy's brain at that, running up as though to try and sneak a peek at what Gaster was fishing out of the coat. "WOWIE, WHAT DID HE GET ME?"

Gently nudging him back for space, Gaster presented a clear plastic bag filled with jagged, curved pieces of…something. Something glittery with odd red and white markings on it. Even Sans went in to get a closer look.

"IT'S AMAZING!" Papyrus snatched the bag out of Gaster's hands and looked it over, the light bouncing off his teeth as he smiled. "…WHAT IS IT?"

"It is a 3D jigsaw puzzle. You put the pieces together. Like-" He pauses, head inclining a little bit. "Perhaps I should show you later. …Why don't you just put this in your room and then get ready for dinner?"

"OKAY!.! I'LL BE BACK IN A FLASH!" He took off for the stairs as fast as his short legs would carry him, actually stumbling over the first step as he climbed up. The door began to swing back shut from the force of it opening, and Sans decided he should probably go wash up too because he didn't like the way Gaster was looking at him earlier when he said he had something else to talk about.

But when he tried to pull away, he felt a holed hand on his arm holding him fast. The boy looked up in confusion.

When Gaster murmured, "Alphys tells me you have been a great help to her in finishing the extractor," he then felt a little sick.

"uh…why would she—say something like that?"

"Words just have a habit of falling from her mouth, I've noticed. Perhaps she thought it would be placating." He did let go though, after a moment. Amusement playing on his features. "What's the matter? You look as though I have fed you bleach."

"—it's—nothing's wrong. –and i'm not really that much of a help, i just…pay attention to things sometimes." Maybe he shouldn't help Alphys anymore. –She should be doing that kind of stuff all on her own, right?

Gaster rested his fingertips on the top of Sans' head, causing him to shudder a little. Remembering the way he'd spoken to them when they first met. But the next time he said something his tone was actually…somewhat soft. Understanding? "Well, we are in limited supply of people who 'pay attention to things' down here, Sans."

He looked up, not quite understanding.

"All I am saying is that I think you would be much more engaged in the lab if you had actual tasks to do."

Sans was unable to keep a vague tone of repulsion out of his voice, like some small child told that they had to eat broccoli before they got their dessert. "like… _work_?"

That prompted a vaguely irritated sigh. "If you are doing it on your own time anyway it wouldn't count as _work._ You might find it very enjoyable. I know I do."

"i'm absolutely shocked that the man with no sense of humor has fun crunching numbers."

"Don't be a smart alec. Just _promise me_ you will at least consider it as a possibility. ….I have a policy of not wasting potential when I see it."

Sans almost objected more strongly, but…it felt less obnoxious when something was being offered to him, instead of being ordered to do it. So though he didn't think he would, he shuffled his feet on the carpet and shrugged. Head bobbing somewhat in a nod.

"Good." Gaster paused, as though there was something else he wanted to say. Something complicated, probably, judging by his expression. But he merely shook his head, turning Sans around and pushing in between his shoulder blades to get him moving. "—Go wash up. I'm ordering takeout tonight."

* * *

 **Author's Note:** I can't really respond to individual reviews with this format and I don't want to spend each author's note going "thank you thank you thank you" for all the wonderful reviews I'm getting but really-thank you guys. I'm so used to writing for fandoms that are either dead or large enough that people in them don't interact much, I'm very unused to getting responses.


	8. Arc III Chapter 1

Arc III: Science

Chapter I

* * *

When the candles on Papyrus' cake fizzled and popped back alight, he shrieked in outrage and immediately blew them out again.

The second time they sparkled back up he knew to blame Sans, smacking him with the card that Arbogast had given him yesterday.

"heheheheheheheheheh."

Gaster muttered something to himself in wingding—to Papyrus it sounded like "Last t—me I -ust-Sans wit—e candle-" before putting out the cake with one calm huff of breath. Drizzling smoke wafted up among them before they flared up a third time and Sans began to roar with laughter.

"I WILL _SMIGHT_ YOU, CANDLES!" Papyrus plucked them right out of the cake, huffing and blowing on them until he was simply out of breath. When that didn't succeed, he ran over to the sink and dowsed them with cold water, eyes practically bugging out of his skull as he did so. When they were well and truly dead, gone about a minute without popping back to life, he turned on Sans, who had moved his party hat down to look like a particularly large, pointy nose. Much go Gaster's evident chagrin.

"SANS YOU RUINED MY BIRTHDAY WISH!" Never mind that he'd only heard about the concept a mere week ago from Bratty. "I HAD TO BLOW THOSE OUT LIKE TEN TIMES."

His brother merely shrugged, closing one eye in a lazy wink. "well, don't worry bro, that's actually like ten wishes right there."

"There is no such thing as wishes. Those girls were playing a prank on you." Gaster had picked up a serving knife and started carefully cutting the cake into six slices—two for each of them. Since he "hadn't thought it prudent" to invite anyone else.

…That was alright. It wasn't like Papyrus had a lot of friends anyway.

"no no, papyrus still gets wishes because he's not as old as you are." Sans slid off of his chair and went to the table where they had set their presents for him. Papyrus wasn't sure why they wrapped them (clumsy and hasty effort though Sans' was). He could tell by the shape that they were books. They could have just taped some paper over them and he would still have been surprised. "don't tell anybody what they are though, bro, otherwise they won't come true."

"You are speaking nonsense." Gaster was carefully putting their cake slices on some slightly battered paper plates, now. "Supposing for the sake of argument wishes _did_ exist, why would telling them to someone ruin their capacity to come true?"

"THEY ARE _MY_ WISHES!" Papyrus hopped into his chair and adjusted his birthday crown, puffing up a little bit and sticking out his chest. "THEY'LL COME TRUE BECAUSE I'LL MAKE THEM! …RIGHT?"

"If you _make it_ come true then it does not count as a—"

"that's exactly right, papyrus. they'll come true because of you." Sans plunked the two book presents down on the table, climbing back up to his seat as well. "we should open these up while we're eating the cake."

"BUT SANS—"

"unless you don't think you can eat without getting them all messy?"

He almost objected, because that was exactly the risk that one was taking when handling presents alongside food, but then he recognized the challenge in the question. Papyrus clacked his teeth together, clenching his fork in his fingers and stabbing it into the slice of cake set out for him. "NO, THAT IS THE EXACT OPPOSITE OF WHAT I THINK."

Sans had already started chewing on his own slice, muttering to himself, as though surprised, "hey this actually came out pretty good." Their father poked at his as though he expected it to bite him, but then eventually he started eating too.

Mouth full of cake, the birthday boy asked "WHICH ONE SHOULD I OPEN NOW?"

"Mine first." Gaster slid his present towards Papyrus, who carefully pushed away his plate of cake to make room. "You are very difficult to shop for."

"you could have literally bought him a sock."

"I wanted it to be _special_."

The wrapping tore easily, though the tape irritatingly stuck to his fingers despite multiple attempts at prying it off. When the package was fully uncovered, he turned it over in his hands. Not quite understanding what it was—there were no pictures on the front, not like the comics Alphys sometimes showed them. …Although few of those pictures made sense to him either.

"ADVAN…KED…PUZZ—"

" _Advanced Puzzles for Cerebral Minds_." Gaster smiled and opened the book, pointing down at various parts of the page. "This contains instructions on materials, measurements, executions, and uh…pictures. –The reading level is a little high for you, but—"

"THANK YOU!" The thanks came before he'd even really looked at it. Sometimes, if they talked back or did something wrong their dad got a disappointed look on his face that made Papyrus uncomfortable somewhere in his rib cage. He was less likely to make the look when they showed gratitude for things.

…And Sans never did so that made it Papyrus' job.

It did look like a fun book, though. Full of ideas, even if the words were big. "ARE THERE ANY CAKE PUZZLES IN THIS?" He took another bite of his own cake, the exceedingly sweet frosting hurting his teeth a little.

"—There are, in fact. Although they call for Bundt cake."

"WHAT IS BUNDT CAKE?" He displayed his half eaten cake piece. "IS THIS BUNDT CAKE?"

"No, it is not. Bundt cake is—well I'll show you later."

"just be sure not to kick us out on our _bundts_ while you do it."

He almost shoved Sans out of his chair, furiously scraping frosting off of his fork with his teeth. " _SANS."_

"Out on your Bundts? What does that mean?"

"well—"

" _DON'T ENCOURAGE HIM IT WAS THE LAZIEST MOST UNINSPIRED—"_

Papyrus was soon interrupted by his brother jabbing him lightly in the ribs—handing the second present over as though it was a peace offering. "you'll like this one too i promise."

"REALLY?" Sans' wrapping was so poorly put together it practically fell off on its own the second he ripped at just a little bit of the tape.

The noise he made upon seeing the contents hurt even his own hearing, squealing and getting off of his seat so he could hop around a little. _"WOWIE!"_

"…? What is it?" Gaster took a step out of his seat, although he didn't dare take the present out of the boys hands with how excited he was at the moment. "What did you get him?"

" _fluffy bunny."_

" _What_?"

"FLUFFY. BUNNY." It wasn't particularly new—Papyrus had seen it once a long time ago, in a store window when he and his brother still didn't have so much as a penny to their names. He hadn't been able to get it then—theft was out of the question-and he'd wailed about it for a while.

But Sans remembered.

"THANK YOU THANK YOU THANK YOU." Maybe he should have stopped running and jumping around, waving the book in the air, before he broke something. …But he had too much energy. He might explode if he didn't wear it out.

At the very least he tossed his present onto the table so he didn't accidentally break it or tear it in his enthusiasm.

"they're thinkin' about making a second one, you know," Sans half-mumbled from where he sat, pleased grin stretched over his face. "maybe i'll get that for your next birthday."

"I hardly think this is in the spirit of getting older." Gaster leafed through the book with an appraising expression on his face, briefly reading its contents to himself. Before he could get too far, however, Papyrus snatched it out of his grip.

"YOU'RE GOING TO SPOIL IT! I DON'T WANT TO KNOW HOW IT ENDS YET!"

Carefully, Papyrus set his prize on top of the puzzle book, making sure the two of them were as evenly squared as they could be with their different sizes. Then he started shoveling the rest of his birthday cake into his mouth. Still standing. There was still the second slice left, but he was no longer interested in it. "WE SHOULD HAVE DINNER NOW."

"dinner? after cake?"

"NYEH." He looked up at his adoptive father. "WE CAN HAVE THAT ONE DINNER, RIGHT? YOU PROMISED."

"Of course." Gaster smiled down at him a little crookedly. "…How about you set up everything? Because you have so much energy right now. […Pr—bly th- cake'- fa-lt]"

"OKAY!" He didn't even really need to be asked—he know where everything was and everyone else did stuff slowly anyway.

There were several grocery bags available to pull things from—most of them stashed under the counter. He could feel eyes on him as he pulled each one from their place and arranged them on the surface, nearby the oven. By the time he was finished they were starting to overcrowd, almost falling to the floor. But he was getting to be tall enough that he could arrange them better so none did.

"what's all that?" A flicker of interest seemed to spark in Sans' eyes as he watched, Gaster walking past him into the kitchen area to start assisting.

"These are all the ingredients we need for Papyrus' special birthday dinner."

"WE'RE MAKING SOUP!"

"Yes, yes. We're making soup." Gaster patted him on the head while getting a large pot around, flicking on the oven burner. "Alright, first we're going to need some water. …And a spoon."

"CHECK!" Papyrus tossed the spoon into the pot first, which the taller skeleton caught before it could clang to the bottom. Then he went for the water. "DO WE FILL IT UP TO THE TOP?"

"Hmm…"

The recipe they'd found at the dump wasn't particularly helpful in that regard…Partially because it was torn in half. All of the instructions were there, of course, but all of the ingredient measurements were on the missing half. In addition to the picture of what it should look like.

"…Maybe fill it up halfway. We have to leave room for the other ingredients, after all."

Papyrus nodded, going to grab their pitcher from the fridge and fill it up from the sink. As he did so he glanced towards his brother, who was still watching the both of them from where he sat at the table, bony cheeks in his hands. "AREN'T YOU GOING TO HELP?"

"naaaaahh."

"He would just get in our way, dear boy. –Now—" The recipe paper crinkled as he smoothed his bony finger over it, eye quickly scanning the next paragraph as his other hand poured in the water. "We need…a good helping of scallions in next. …It doesn't actually say that but I happen to like scallions so we're going to add a lot. Yes?"

Gaster had started stirring the pot quite vigorously as the next ingredient came up. The water swished pleasantly—making Papyrus a little hungry, in fact. "THAT SOUNDS FAIR. –WE SHOULD DO THE SAME FOR THIS ONE!" He tossed in a few potatoes of, making a soft plunking sound as they got mixed into the soup. "I LIKE POTATOES."

…That was how the rest of the venture went. –Making judgment calls on the ingredients based on how much they liked the individual components. Some extra bacon, a little bit less of sour cream, a sprinkle of salt, a handful of pepper for punch.

"HOW MUCH CHICKEN BROTH DO WE ADD?" The carton was a little heavy in his hands as he brought it to bare, empty grocery bags littering the counter at this point.

"…Probably enough to fill the rest of the pot?"

Sans snickered behind them.

The recipe hadn't said whether or not the mixture was supposed to explode or not at the end. But from Papyrus' experience with human things, it made perfect sense that it did.

* * *

Later that evening, after they had cleaned up the mess and substituted their dinner with some takeout, Papyrus had dragged the both of his family to the living room to look over his new book. –The bunny one, for some reason. Gaster would have thought him too old to be entertained by such childishness, but then what exactly did he know of developmental psychology? It wasn't like he'd had much of a childhood himself.

They'd all plopped down on the couch, Papyrus sitting in the middle and pulling the book out across his lap and looking over the pictures in the opening. Then he'd nudged Sans, pushing it into his hands and demanding that he read it out loud instead.

"Giving up already?" Gaster couldn't help a slight tinge of amusement in his tone. "I was looking forward to seeing you read it."

"NO, NO!" It was also amusing that the boy seemed almost desperate to not give off the impression that he couldn't handle a picture book. "I JUST—LIKE IT WHEN SANS READS."

"i do the funny voices." Suddenly an impishly grinning face filled up his field of vision, held up by two small bony hands and the elbows attached to them resting on the top of the birthday boy's skull. "can you do funny voices?"

"-How are voices funny, Sans?"

"SANS GET OFF. –DAD YOU HAVE TO LISTEN."

 _Fluffy Bunny_ was, in fact, the first book officially published by a monster in the underground, rather than the usual work fished out of a pile of garbage and restored. For that reason, though it was immaculately clean and new, the quality wasn't exceptional. The pages didn't hold together too well, the color went outside the line work a little, and the writing was all done by hand. Still, it did have a bit of a rough charm all its own. Even if the plot and characters were simplistic drivel.

Sans delicately turned the pages as he read, carefully crafting a different inflection and accent for each character as he read their part. Though he wouldn't exactly call himself an expert in storytelling himself Gaster could tell that it was something he was practiced in doing. He briefly wondered if they had any picture books to their name at some point.

It was…relaxing, surprisingly. Papyrus rested with his head against his side, eyes almost as big as dinner plates while he listened in. Occasionally objecting when he could tell that Sans was making his own additions or puns in the script. Most of them he didn't get—perhaps they were recognizable to Papyrus because he had heard them before. Many of his complaints did seem to be along those lines.

But the ones that Gaster did get, he laughed at helplessly. It hurt his ribs, but it wasn't bad. It was one of those rare evenings that was a waste of time yet didn't _feel_ like a waste along those lines.

Then something odd happened just as Sans was getting through the last two pages of the book.

He was playing the voice of a small deer, who Fluffy Bunny had befriended, one whose voice evidently required a great deal of nasal tones and high pitched squeaking. And he'd cut himself off mid-sentence.

The noise that had come out of his mouth at that moment was like a broken chew toy, an empty, hollow squeak. It completely interrupted the flow of the story and made all of them silent for a moment, frozen and staring.

Sans' pupils flickered out, putting a hand to his mouth and coughing experimentally several times. "uh. uh."

His voice cracked.

Papyrus made a small gasp of horror at that, clapping his hands to the sides of his face as his brother was clearly starting to panic. "DID FLUFFY BUNNY BREAK YOUR VOICE?"

"uh."

"OH NO. THIS IS ALL MY FAULT. I'M SO SORRY SANS!"

And then Gaster suddenly started to chuckle. "I know what is going on here."

The two of them stopped their minor hysterics to look back at him, and that just made him laugh harder.

"what are you talking a _bo_ _ **u**_ uu ** _t?"_** Sans actually ended up clapping his hands over his mouth at that, coughing.

"Your voice is changing. Puberty." He sucked in air through his teeth, tilting his head a little. "Quite honestly I thought it had already happened, you are past the age where I would have expected it to. …Goodness, you are going to have a magnificent baritone."

" _i don't know what any of that means."_

"You're just growing up. About time, too. …I was starting to think your less than stellar previous living conditions were stunting your growth." Gaster lightly rapped his knuckles on Sans' head and the smaller skeleton made a sputter of annoyance.

" ** _wh_** e _n_ is it going to _stop?"_

"Probably about a year?" He shrugged. "I wouldn't worry about it, there are a few things you can do to avoid the issue. _Not_ talking is one of them. I have other ideas but—I am not sure they work on someone without vocal chords. …Which is interesting, considering voice cracking requires vocal chords. Never thought to look into that… [Maybe I can run some experiments on your neck bones and see if that alters anything-]"

"—hey shh!"

"…Hm?" Sans was pointing down by Gaster's side, and, the brow of his left socket lifting, he looked down to see Papyrus sleeping there. He must have drifted off during the conversation. He added, voice much quieter, "Ah. I see."

…Admittedly the sight was…strangely endearing. The boy had stuck his thumb in his teeth, curled up like a dog around a radiator. Gaster had never been a radiator before. "...I am surprised. Sometimes I hear him pacing in his room at night. I assumed he was not able to sleep."

"you just gotta tire him out enough."

"I will keep that in mind for the future." He gently rested a hand on Papyrus' skull. His chest felt a little tight when he saw him move a bit, thumb falling out of his mouth and arms going to wrap around his waist.

Maybe next time they had "story time" he could be the one reading.

The feeling faded, after a moment. As charming as it was to have a child sleeping on his side it made getting up impossible. He glanced back at Sans, who once again held his head in his hands, eyes half closed.

"…Okay now tell me how to get up without waking him."

That made Sans chuckle quietly, stopping when the sound cracked unevenly. Then he shrugged, turned around, and started walking towards the stairs.

"Seriously, Sans. I want him to be able to sleep but I cannot stay on the couch the entire time."

"g'night doc." The short skeleton merely waved a hand in his direction as he left.

"Sans?" It was actually very difficult for him to carry his voice without raising it to a level that would wake Papyrus. " _Sans you get back here this instant you little—"_

* * *

 **Author's Note _:_** Little bit of a fluff chapter, but they're not gonna have too many fun times in the latter half of the fic so might as well have some now. **  
**


	9. Arc III Chapter 2

Arc III: Science

Chapter II

* * *

The first sensations that assaulted them as they took their first steps inside the Core was pure, white light and the smell of ozone.

The next sensations were an oppressive, vibrating hum and blanketing heat. More humid than the burning of Hotland.

Gaster strode forward without stopping, his hands held studiously behind his back. Sans paused, allowed the feelings to wash over him and sensing briefly that was in danger. But he quickly pushed past it, jogging a little to catch up and trying not to drag behind while he looked at the panels and circuitry lining the walls.

It was strange to see the Core on the way to the lab so often and then…finally be inside it.

Today was supposed to be something else—A discussion on magic, now that Papyrus had finally started showing that he could use the blue attacks. But an issue had come up soon after arriving in the lab. Something going wrong in the inner workings of the Core that required Gaster's attention. He hadn't been paying close enough to attention to know what exactly-just be startled into following along when the doctor had tapped his shoulder and told him to.

-It wasn't that Sans was ungrateful for the distraction. Magic was an uncomfortable topic, and now instead of being examined like a bug under glass he got to learn about what powered the entire kingdom. …It was just. Strange inside it.

Not to mention he didn't have his brother with him. Papyrus had been made to stay back at the laboratory with the other doctors. "Your brother is still at that age where he likes to _play_ with things," Gaster had said. "It would be dangerous if he pressed something he shouldn't.

When Sans was younger he was a master at pressing buttons that he shouldn't. Sometimes he even dabbled in pulling levers. …But not so much anymore, he did have to give him that.

Their shoes clanked on the walkway as they made their way in deeper.

"There are two entrances to the Core," the scientist was saying, his voice detached and almost disinterested. Of course, he must have already been inside many, many times before. He wasn't be inundated with completely new experiences. "The first is the one we just came through, from the lab. The second is through the very edge of Hotland. Near the path back to the capital. …The former is so much simpler though, don't you think?"

He'd never gone through the other. Sans just shrugged and made a noncommittal hum, merely grateful he was just in a T-shirt. He didn't know how Gaster could stand the Core's temperature with a lab-coat on.

"what exactly are we supposed to fix?" The notes and panels and circuitry all looked so intricate and fragile Sans had no idea where he would even start. He had no idea where _anyone_ would know where to start. God forbid there came a day when there wasn't the machine's creator around to make repairs. "you didn't bring any tools with you."

"There's nothing that's specifically _broken_ , per say." Gaster pauses to enter something into one of the screens set randomly into the walls. Wingding. "Just a few things that are malfunctioning."

"what's the difference?"

"I have countermeasures in place to solve the problem that do not require any tools." The pace doesn't stop through the conversation, and Sans tries to hear him over the sound of him jogging again to keep up. "To put things simply the Core converts the geothermal energy of the Earth's core into magic. Then it diffuses this magic all throughout the kingdom. -Humans have their own processes to produce electricity, as they are incompatible with magic."

They took a hard right turn, a few lights flickering green as they passed. Without even pausing Gaster pulled down a switch and the colors changed to orange.

"In order to prevent overheating the Core has a series of pressure release valves. They blow off the excess heat and magic and temporarily allow the systems to cool. These are automated. Sometimes, however, the circuitry will glitch from the temperature and keep the valves shut. …Currently Dr. George is in negotiations with Snowdin to see if we can't simply apply ice to the problem, but until then we need to throw the manual releases to make sure it doesn't explode in the next month."

It wasn't really all that simple but Gaster had probably cut out as much of the long, unnecessary wording as he was able to.

"…so you're saying we gotta get the core to let off some _steam_?"

"That is precisely it, yes."

Sans groaned and shook his head, wiping his hand over his face.

It was almost comical just how big the place was as they made their way through it. The heat, surprisingly, was something that he could get used to, if he didn't think about it. The most uncomfortable feeling remaining from that the condensation slipping down the back of his skull as they walked.

Finally, it seemed they'd arrived at their destination, Gaster slowing and finally glancing back to make sure that his charge was keeping up.

"Pay attention to what I'm doing."

"is it complicated?" He did take a few steps forward as he heard a small panel clang open on the wall-one marked with red and a small symbol he didn't recognize. The interior was filled with an odd assortment of wires and buttons, all of them color-coded. It was unfortunate that he simply didn't know the code.

"Not really. …Not for me. I merely think it is educational." Gaster slotted a few wires back into their correct places, sliding down a switch partially buried beneath them. Though he wasn't explaining any of the things he was doing, it was at least easy to memorize the movements.

"Incidentally—" Sans sighed and rolled his eyes as he heard the doctor switch to his other font. "[-How ha- you been doi-g with y- wingding st-dies?]"

"look is it really that necessary to know? you can speak with aster, can't you? do you just hate people understanding you?"

"Yes." Gaster did look satisfied at the knowledge that he clearly had been understood, though, and in spite of himself it did make Sans feel good to see a slight smile pull at his features. "It's like speaking in a secret code, don't you think? My coworkers can be fairly loyal but sometimes you have to be cautious of those who would steal your ideas. Or oppose them for other reasons."

A loud hiss started up at that, and Sans felt himself being tugged out of the way of a blast of steam by the back of his shirt. The small door clanged shut as he finished, the two of them proceeding onward to the next manual release panel.

"what's that supposed to mean?"

"People just have a funny way of thinking about the things I suggest."

It was a somewhat ominous note to end that line of thought on, not that his guardian seemed aware of that. He followed a small line in the floor to their next destination, humming disjointedly to himself in a way that synced up with something in the sound of the Core. It occurred to Sans that the tune the man always seemed to have on his mind was this very same song. …If it could be called that. He wanted to tell him to stop but instead he let his hand drift over the wall. His fingers caught on the panels of another elevator, one that led to a higher level of the facility. They didn't enter it.

The next one was on a dead-end hallway, next to a small, empty trash-can. Gaster easily flipped it open, again fussing with the wires and some sliders. The exact same sequence, at least at first.

"Alright, now this one is a little different from the others because-"

"why are you telling me all this stuff?"

The question might have seemed a little sudden. But it was the kind of thing he had on his mind often. Gaster didn't turn around, going silent on his explanation and focusing on activating the release. "I told you. It's educational."

There was nothing but a low hum for a minute, before Sans took a step towards him, shoving his hands on his pants pockets.

"look, i know my brother likes to ignore or forget things that don't suit him because he's a kid but i'm different alright? i'm older." Ignoring the way his voice now cracked when he raised it too much or spoke too fast. "you don't want kids. or at least you _didn't_ when you adopted us. and the way you keep acting like we are, it's-it's creeping me out."

Gaster turned around, broken eye narrowed as he rubbed along the scarred fissure above it before turning back to his work. "It disturbs you that I am treating you like my children?"

"it 'disturbs' me because i know you don't _mean it_. so i don't know why you're _doing it_."

Again silence. Or as close to it as there could be here. Sans tried again.

"are you just hoping you'll get something out of it? are we some kind of investment?"

"Yes. You two are an investment."

The immediate reaction that Sans had to that must have been obvious and unguarded on his face, because Gaster scowled and retorted quickly, "Don't look at me like that. _All_ children are investments. A massive amount of time, finances, and effort that only pays off when they come to adulthood. …Sometimes it never pays off at all. -The point being that just because I am investing for different reasons doesn't make me any different from most parents."

"you're a piece of work."

"I am not _completely_ devoid of sentiment, you know." Another hiss, another release of steam-this time at least down the other end of the corridor so Sans didn't have to move-and Gaster closed the panel. Wordlessly he leaned against an empty wall, folding his arms and shrugging.

"…Do you know it took me several years before I had the Core fully operational?"

The comment seemed to be completely out of the foggy white under the walkways they had just traversed, the doctor not even looking at Sans anymore but the scuffed tile on which they stood.

Sans shook his head.

"During that period of time I practically…lived in here. Slept here. Ate here. I almost forgot what the cave ceilings looked like. This was me. This was my life."

Well that explained one or two things.

Ignoring the expression on his charge's face Gaster kept going, a faint smile spreading on his own features. "I cannot-express the pure, unadulterated pride I felt when it was finished. To see the lights come burning to life. To know that this would not have existed without me. Can you imagine that? …Have you ever felt proud of anything in your entire life?"

Sans was not expecting the question-not expecting any questions at all-and took a moment to respond. "there's one thing. that i'm proud of."

"If you take a job in the laboratory then you can have many things that you are proud of."

"are you bringing that up _again_?" He turned away for a moment and was met with another expanse of hallway, threatening to swallow him if he didn't memorize the path. He sighed and turned back.

"…Working with me on these marvels is my olive branch to you. Please accept it. I may not have much warmth to offer but I do have this."

So he offers Sans a job and Papyrus cake. "yeah well good for you. it's plenty warm in here."

Gaster's white eyes fixated on Sans for a moment, expression unreadable. Then he started chuckling to himself, swinging back around to continue on.

They didn't have much more after that. Sans kept his quips to himself, somewhat consumed by his thoughts and watching as the manual release valves were activated, one-by one.

His memory was great but navigating the Core wasn't just an issue of size. Though the building spread over several floors and hallways like a labyrinth, the real problem was how uniform each of its features were. Every doorway looked precisely the same. Every tile was pristine. Even the dirtied footsteps of his sneakers left no trace on its polished surface, the grime burning away with a soft hum. The resting audio sounded exactly the same no matter where you went.

Only minor markings, trashcans, and monitors marked out your location at any particular time. Things that Gaster could pick up on in a snap-things he'd obviously had a hand in placing. He probably had the entire layout permanently lodged in his brain.

Finally, he'd declared amidst the noise of the panel snapping shut, that they were finished. It was lucky Sans kept his hands in his pockets because it looked as though Gaster was thinking about taking his hand and leading him along like a small child when he passed by him. But that didn't happen.

They passed over a catwalk on the way to the exit and something moaned in its depths.

Gaster muttered something to himself in wingding. "-Stay there. I need to go check on something before we leave. It will only take a minute."

"you sure you don't want me to _watch_?"

The glare he got back in response made him chuckle, and the only thing he watched was Gaster's back as he pulled back into the inner workings of the building.

So he turned his gaze outward.

What lurked in the space under the Core's walkways? Was there any way to get down there?

Sans looked over the railing into the steaming white below. Tubes and wires were visible along the far wall, sinking into the abyss. No end in sight-maybe it went all the way down to the very center of the world.

Sometime, he'd have to ask how all of this worked. How something can produce enough power for the entire underground without massive amounts of consumption and waist. It wasn't like they had a lot of places to dump things.

As he leaned over, consumed with his thoughts, Sans felt, with a sudden sickening squeal, the railing under him give way. Popping free and swinging out as though intending to deliberately throw him off the walkway. His soul rattled in its cage, air sucking in through his teeth. He didn't have a chance to scream, arms wind-milling and starting to tip over the edge.

He would fall down, down-

 _"_ _Don't fall."_ Bony fingers encircled his waist and jerked him back onto safe, solid ground, an urgent and concerned tone that Sans had never heard him use in his voice. The white void pulled away. "-Aren't you supposed to be the cautious one?"

His head was swimming, and as he was easily picked up, ribcage almost crushed in the hold, he was reminded of how insignificantly small he was.

"what'll happen?" Squirming out of his grip the second that he knew he was safe, Sans' voice sounded dry, and shook. Just a little. "what'll happen if i fall in?"

"You'll shatter into a million pieces. …From the impact at the bottom. That is if the excess magic doesn't burn you into smoldering slag before you get there." When he was let go he turned to face the doctor, the man's good eye creased similarly to his broken one. The eye-lights therein completely gone. "What do you _think_ would happen?"

No words could come to mind. He was imagining what it would be like.

Gaster sighed, wiping his scar again and standing up taller. "Let's…let's go back. My work is done. …I will show you more when that railing is fixed, if you wish."

* * *

Sometimes it was difficult for Gaster to phrase his explanations in a way that were simple enough for Papyrus to understand. Not because the boy was stupid. No it was very clear to him upon any amount of observation that that was not the case. But because his intelligence functioned in…different ways than his brother, who could pick up the terminology so quickly. Characterized largely by naiveté and looking at things in the wrong light.

"SO MONSTERS GET THEIR MAGIC FROM HUMANS?.?"

It would help if Sans, who clearly understood just fine, would actually assist in explaining it rather than sitting there chuckling in the corner.

"No. Not they do not. I merely developed the classifications for monster magic based on the properties of human souls as recorded down in some primitive investigations from during the war."

The classification system was not _ideal_ , of course, and the connections between that and the properties of monster magic were flimsy at best (how exactly did the freezing qualities of green magic correlate to kindness?), but it was at least a good way of simplifying things.

Or so he'd thought.

"SO SANS IS A PATIENT PERSON BECAUSE HE COULD DO BLUE ATTACKS EARLIER? AM I PATIENT?"

"You are the opposite of patient." He dragged his fingers down his face, frowning. "You are focusing too much on the soul qualities rather than the magic qualities."

"-Are you okay Sans?" Dr. Likker interrupted quite suddenly, his normally wide, buggy eyes crinkled somewhat in concern as he passed by, a large stack of papers held to his chest in an attempt to keep them from all slipping out of his grip at once. "You've been awfully quiet. Did something happen while you two were out at the Core?"

Gaster interjected, a small bit of spite lacing his tone, "Oh don't mind him. His voice started changing over the weekend and he's embarrassed."

Sans shot his most hateful glare the older skeleton's way and probably thanked whatever deity there was above that he didn't have blood vessels to blush with.

"you can just-"

"-My _point_ is that magic, like human souls, can be classified into categories based on color, which corresponds to particular traits. That there is a correlation between most human soul colors and magic categories is aside from the point, but it can serve as a mnemonic exercise," he cut him off, ignoring the look. "You just cannot take it literally."

"OH." Whether or not Papyrus actually understood, it was too early to tell, but he seemed to have stopped persisting in his misunderstanding for now. "WHAT TRAITS DO I AND SANS HAVE?"

Gaster smiled, chewing on his pinky and sitting back. "Magically, you two have irregularly powerful blue magic for children of your age. To break that blue magic down into its basic composition…"

It wasn't likely that Papyrus would understand everything of this lesson, but nonetheless he was enjoying teaching it. This was a subject, after all, that he had invested quite a lot of time in.

And Sans was, for once, not constantly interrupting him with his sarcastic commentary. Indeed, he even seemed to be paying close attention.

His mind drew back to the conversation that he'd had with Sans.

Investments. Their eyes bright and attentive, arms folded around their legs as they listened.

…Yes, all children were investments.

* * *

 **Author's Note:** I can honestly say that seeing your guys' reactions to my story is about as much fun as writing it. I find myself cackling with glee while reading the reviews.

Also shout-out to my pal Octoya for helping me with the ending of this.


	10. Arc III Chapter 3

Arc III: Science

Chapter III

* * *

Sans slipped inside True Lab with Dr. Arbogast's keycard, long after everyone else had gone back home. Gaster had actually been very good at keeping the promise that he'd made, to spend more time with them either when they were in the lab or at home. …Even if Sans personally wasn't thrilled by that. But tonight was one of those rare nights where his progress required long hours bent over his desk, scribbling and mixing and burning his fingers.

Ironically, it was the first time that Sans actually had something to talk to him about.

The rattling of the elevator shook his resolve, but ultimately he pressed forward. He was probably already heard.

As he strode into the main lab workspace-the only area of that floor left that had its lights on-he heard Gaster say irritably, without turning around, "I thought I told you we would discuss the matter tomorrow."

"doc?"

"-Sans!" He took one look around to confirm who he was talking to before swiveling back to cram his papers back into his desk drawer and locking it, all in the span of a few seconds. Then he finally turned, working eye open in clear surprise. "…I was expecting someone else."

"yeah i figured." Sans craned his short neck at the desk, but everything that was worth snooping around in was already put away. Not that he was able to read wingding yet. "expecting one of your cronies?"

Although that wasn't fair, most of the other scientists were an absolute delight. Especially after Sans had grown up a little.

"Dr. Likker and I had a minor disagreement about something. It is none of your concern." Gaster tapped a battered pencil against his chin, head tilting. "Did you come up here all on your own?"

"yeah. …i was getting on pap's nerves so i wanted to take a walk and then i ended up…walking out here?"

"How unlike you. Friends busy today?"

There was no spite or sarcasm in the comment, the doctor merely turning back around to instead type in some notes with the computer on his desk.

"no. i wanted to talk to you about something."

The _click-clack_ on the keyboard hesitated just a moment as he seemed to process this information. Then he nodded, droning slightly, "Go on. What is it?"

Sans sighed, thinking about maybe just telling him to forget it and head home.

"what exactly would i be doing if i ended up working here?"

Without missing a beat came the reply, "Anything that requires your assistance. With your particular magical aptitude you would most likely be working on a pet project of mine-

"aw geez."

"-but then it would also be influenced by what you personally wish to study. …Within reason, of course. We _are_ supposed to be benefitting people other than ourselves, you know."

"yeah?" He scratched his skull. Looking around at all the machinery in the lab that he currently wasn't allowed to touch. Imagined everything in the rooms that he wasn't allowed to go into. "well i was. ...thinking of taking you up on that offer, i don't know."

Then the clattering of keys stopped entirely.

When the chair swiveled around Sans was actually taken aback by the enthusiasm he saw on Gaster's face-the man's smile spread so wide it almost split his features in half. " _Really?_ "

"uh-"

"This isn't one of your little jokes is it?" Even though it was clear that the man had no idea what kind of joke it would be, standing up and approaching his charge with his hands clasped together. "You mean it?"

"i-yeah i guess i do." He couldn't help but take a single step back. Just out of instinct, almost. He wasn't used to seeing him so enthusiastic. "…i mean its not like i have anything else to do. -you're getting pretty excited about this, doc."

"Am I? I'm not trying to be." The remark didn't seem to dampen his mood much, eyes alight and his right eye twitching oddly as his lid tried to lift.

"well no, it's not something you _try_ to be…"

"I'm, I'm just, I-" He paused. There seemed to be a bit of confusion. Maybe he was unused to feeling like an actual person instead of a cold machine. "…I feel proud."

Sans balked. "of _me?_ "

"Not sure. Of myself, I think?" The confusion melted away to evidently another surge of joy, moving to a doorway on the far end of the room and creeping inside. It looked to be some sort of storeroom for supplies-or, rather, a closet. Not very large, though it evidently did have its own lightbulb, as Gaster flicked it on.

Sadly enough the clarification didn't surprise Sans enough to hurt his feelings, following after the scientist and try to get a look at what he was searching for. "what are you doing now?"

"I bought something for you." His voice was quick and rushed, still heavily distracted. "…Maybe I didn't put it in here."

"you bought something for me?"

At first Sans assumed he was going to be ignored again, before he heard from inside the small room amidst clattering and box shuffling, "Well of course! This is a momentous occasion. [Now w-re is the d-ed thing…]" Gaster made a brief huff of frustration before turning around-smile returning the second he caught sight of Sans again-and then headed for a cabinet back into the lab room. "You have no idea, this makes everything so much easier-" His speech cut off momentarily as he started rifling around inside the cabinet. "-You'll love working here, Alphys tells me how phenomenally bored you are all the time-"

A little dumbfounded, Sans slowly followed him as he went through every storage space in the room. Used to being ignored by now, although to Gaster's credit the reasoning was less obnoxious this time. Growing tired of listening to him mutter, he eventually turned around to go looking on his own-pulling out the drawer to the man's desk.

Surprise, surprise, there was a small, upturned box inside.

"-You get away from that." Gaster pushed past him, fishing out the box with a pleased cry and looking it over for dents. "There it is. I knew I would find it eventually."

"yep, you sure did."

"Hush, I am able to recognize sarcasm now." Sans laughed quietly at the light bat to his head, shrugging and moving back to try and look at the present more completely as the doctor turned it over and brushed over the top. It wasn't wrapped-he could see some writing on it. Size and color.

"did you give me clothes?" Sans let out a dry chuckle. "i seem to recall i've already made my opinion known on you getting me stuff like this."

"Well, perhaps now that I am going to be your direct superior you'll actually accept this one." His smile lightened and pressed the box into Sans' hands. "Open it."

In spite of himself, the expression slowly started to mirror itself on the smaller skeleton's own face. Prying his fingers under the lid and sliding off the top.

"…you're really excited about working with me, aren't you?"

The lab around them hummed contentedly, and he glanced back up. Smile waning only in uncertainty.

"I am." Sans flinched slightly as Gaster patted him on the head. "I didn't always think things would turn out that way but I am…excited?" He cleared his throat. "I promise I will be less emotional when we're actually working."

"i'm sure you'll reserve it for inanimate things." The fabric was stiff against his finger bones as he pulled the coat out of the box, like it was a little starchy. He held it up to the lights overhead, and as he did so they flickered once.

It was clean, white lab coat.

Gaster was wringing his hands, curling his fingers through the holes in his palms. "Try it on."

Sans unfolded the fabric further-briefly looking it over again before slipping it over his shoulders and pushing his hands through the sleeves.

It was a little large on him.

"…i guess i'll grow into it."

* * *

 **Author's Note** : Sorry for such a long wait over a short chapter. Like I've said in the past-I always have like 5 things going on at once (some of them more pressing than others). If it's any consolation, the next chapter is about half written, so that should help it go by faster despite all the other things I need to deal with.


	11. Arc III Chapter 4

Arc III: Science

Chapter IV

* * *

The news spread through the underground fairly quickly when prince Asriel and the human child had died.

Officially, all monsters were in mourning. Work was ended early, today. But despite that there were still two people remaining in True Lab.

One of them was currently scribbling out on several formerly blank sheets of paper, covered with odd symbols and smeared graphite. There was a shape of some sort in the center with several lines connecting pieces of the shape with illegible descriptions-even he wasn't exactly sure what he was trying to make.

It had not been a good day for Gaster, but that wasn't because he'd loved and trusted in the pair of children like almost every other monster in the entire kingdom seemed to have. He was smarter than to be taken in by Toriel and Asgore's political propaganda, though such words might be a bit harsh to describe it with. No _one_ human was going to save all monsters from their prison of despair and stagnation.

Save for, perhaps, if they were lying on an operating table.

Sadly such a thing was out of his reach by now.

Cutting off the work day early was chief among what soured his mood. Suffering never stopped them before; he didn't know why it should stop them now. Rather, now was the sort of situation that should strengthen their resolve.

These feelings he had at the announcement—a strange grief rooting in his stomach—were also a supreme annoyance. Another reason why both eyes were firmly creased, eyelights flickering as his focus jumped from word to word.

The king had made a decree—well. He'd said some things that had been taken as a decree. Some others had begun to celebrate at his newfound resilience but Gaster knew better. Once the initial pain and anger had passed the soft-hearted old goat would regret every word. If he wasn't regretting it already.

To deal with their conflicting emotions, most of the laboratory staff had gone home to be with their loved ones. That was also irritating. As though their work wasn't important. As though the fact that they weren't anywhere close to the goals he'd set out wasn't the _precise reason_ why this tragedy had happened. To some small consternation he found that only one person was willing to remain and work alongside him, and it was one person that wasn't useful for any of his ongoing projects.

Right now she was working on mending some new mechanical irregularities with the Core. They'd been taxing the system too much recently, trying to run so many things at once. Particularly considering the persisting issues with cooling it. He'd had to put the lighting system in power-save mode to be safe, putting an admittedly eerie atmosphere over everything. Just enough to see by but not ideal working conditions.

Unable to get too much done he had taken to brainstorming. The situation in the underground had gone from hopeless to desperate—such things always forced him to come up with new ideas, and expand on old ones.

Right now though he was regrettably fixated on something he wasn't quite ready to attempt yet and another something that was impossible.

The former, of course, should be top priority. Considering the current state of the kingdom's opinion on humanity, it was only natural. The public would certainly cheer him on. Asgore…Asgore would privately prefer the latter project, he supposed. He always preferred a happy pipe dream to cold reality.

Although as far as pipe dreams went this one was rather seductive…

He was suddenly interrupted from his thoughts at the sound of shuffling feet padding back into the room. Still focusing on his work he said, sharply, "Status report, Alphys?"

When he glanced back towards her, he saw her adjust her glasses, looking everywhere but at him. "All fixed up. I think…I mean it w-was a little hard to-to navigate but I followed th-e plans so it should be okay?.?.?"

"Is that a question or a statement?"

"…Uh…"

Not intending to be cruel he muttered, "It would not be very helpful of you to do repairs that I would have to go back and correct, yes?"

"-n-No! No it…-Yeah it works fine now, I know it does."

"Good."

There was a moment of silence as he returned to his paper, pulling out another sheet from his drawer. And then,

"Where are Sans and Papyrus?" Alphys always made a valiant effort to keep her vocal tremors well contained but he could tell she was nervous. About what he still didn't know, nor did he really care. Not at the moment, anyway.

"I sent them home." Perhaps she had been hoping for other people to talk to whose interests at least somewhat matched her own. Pity. Then she was to be disappointed.

"O-oh."

"They would just be a distraction right now, anyway."

As he scribbled down a few more observations he heard her say to herself, "S-so it's just y-you and me right now…"

"It appears that way, yes."

"So I should-"

"-The extractor is finished?" He turned back to look at her, the force of his gaze evidently pushing her back a step. She nodded, flustered, and he turned back to his notes.

Gaster realized with a start that everything he'd been writing was on the pipe dream project. The fantasy. Not the weapon that he was designing.

"…Huh."

…It could be possible…Yes it very much _could_ be possible. If he could—if he could only-

"…Oh Dr. Alphys?"

His voice was light and inquisitive, steepling his fingers on the desk and glancing back in her direction. She stood frozen in the doorway to the hall, likely intending to go to the vending machine for a snack. For some reason with the mindset he was in, the fearful way she looked towards him as though expecting to get chastised for something was amusing. And so he smiled a bit wider.

"Y—yes?"

"Come this way, please." He made sure to sound as completely calm and emotionless as he could, however. Stress made it difficult for her to function, he'd noticed. "I would like to borrow your expertise, if I may."

"M—my expertise?" Alphys seemed to flush at that, as though he'd given her some high praise. "Um…okay?-?"

As he listened to her walk, dragging her tail along the floor behind her, he tapped his fingers on the table and gazed over the idea sketch he had created. It would be complicated—he would have to keep a close eye on her the entire time it was under construction. And he would need it to be secret, at least until he was able to make it seem more reality and not deluded ramblings of an arrogant scientist.

The golden yellow dinosaur monster nervously came up next to him, her fingers interlaced to keep her arms from shaking, and he reached over to put a hand on her shoulder.

Perhaps it was a misstep. The contact seemed to make her knees buckle before she righted herself.

"—Alphys how would you like to be put on a very secret, very important project?"

"M-me?" If she blushed any harder he suspected that there would be no blood left for the rest of her body. At least the prospect seemed to please her. Or fluster her. He wasn't entirely sure why for the second response. "Oh b-but—but Dr. Gaster I'm just an—an amateur. I've only been an official doctor for-"

"Nonsense." He patted her on the head this time. Gaster had always found the shape of her skull to be very amusing, tapping his fingers on the ridges at the back of her head after a moment. She trembled and he retracted his hand. "You may be lacking in experience but you make up for it with creativity and dedication. Truth be told you're probably the only person with the mechanical skillset I need that could handle this."

"R-really? That's-! That's so kind of you to say." He could tell she was trying to read his notes, craning her head over the table as much as she could with her practically nonexistent neck. It wouldn't do her any good—they were always all in wingding. "Especially coming from someone so—so—"

"Brilliant?" It was an adjective she liked to use.

"—Yes. Um—brilliant and esteemed and—far, far smarter than me."

He couldn't deny a bit of pride at that, even if the praise was coming from someone who was clearly being self-effacing. But he only spared a moment to preen at her words, wrapping his arm around her shoulder and drawing her in. She squeaked.

"As I said before, however-this is a very, very secret project. I don't want you telling anyone about it. The only person who has a right to know is Asgore. Can you keep a secret, Alphys?"

* * *

"WHY WAS EVERYONE SO SAD TODAY?"

Papyrus didn't see the look Sans gave him, engrossed in his coloring with his head supported by his fingers curled up under his left cheek bone. There were ink stains all over his fingers in black, purple, and blue.

"…still wondering about that?"

"YEAH." None of the color was inside the lines, of course. But then he figured that was sort of the point. He'd just obscure the linework. So, better to color everything outside of the actual figure on the page. There's a crude dog in the corner. "NOBODY WOULD ANSWER ME WHEN I ASKED."

There was a bit of silence on his brother's end, and Papyrus started to think that maybe Sans didn't know himself. Gaster certainly hadn't seemed interested in explaining, having Arbogast walk them home and secluding himself back in the lab.

"…i guess something sad must have happened, huh?"

One page finished, Papyrus turned to the next, painting in some red streaks in the corner. "THAT MAKES SENSE."

Another period of silence, and then Sans made a coughing noise, moving over to plop down in front of the coloring book. Legs crossing, elbows on his knees and face on his palms.

"there's some good news though. -well, sort of. i was gonna tell you last night."

He glanced up, eyeing his brother's lazy grin. "SORT OF?"

"yeah."

Now he needed to add blue, swirling the color around the lady in the picture. "WHAT IS IT?"

"i got hired."

The orange pen in Papyrus' hand almost flew into the air as he sat up, eyes bugging out of his skull. "YOU GOT HIRED? YOU GOT HIRED WHERE?"

Sans chuckled, moving to sit back on his haunches. "i got hired at the lab. …i'm gonna be doing science."

"YOU'RE GONNA BE DOING SCIENCE?" He was so excited that for a moment Papyrus couldn't even think, bones rattling a little as he struggled to stand. "SANS THIS IS AMAZING. -SANS YOU'RE GOING TO BE DOING SCIENCE! -SANS-!"

And then Sans said "oof!", followed up by a slightly cracked sounding, "you're crushing meeee".

"YOU'RE NOT BEING LAZY! I'M SO PROUD OF YOU!" At moments like this he was too excited to even notice as he clutched his brother's bony frame that he and Sans were now almost the same size.

"heheh. well, the jury's out on that one. i might end up just being a lazy scientist, you know."

"SANS!" He lightly smacked him, letting go and pulling back. Even though he couldn't help smiling a little bit still. "NO! YOU'RE GOING TO BE A GREAT SCIENTIST. YOU'RE ALWAYS HELPING ME WITH THOSE WORKSHEETS THAT DAD KEEPS GIVING US! SO DON'T BE LAZY!"

"oh gee alright. if that's what you think i should do." Sans nudged the coloring page that Papyrus was working on, as though thinking to himself. Then he looked up again, a sort of gleam in his eyes. "-i got a labcoat too, you wanna see?"

" _YES_." His little bones rattled a little bit when he jumped, grin threatening to split his jaw in half. "YES, SHOW ME YOUR LABCOAT!"

" alright alright." Sans hopped up from his kneeling position, striding up to his room where he'd been keeping it. Papyrus resisted the urge to smack his brother on the back of the head and yell at him over his bad hygiene when he saw the state of the place-wrappers everywhere, bed covers all in disarray. -This wasn't about that. This was about the box underneath his bed, the one with the nice labels on it. "here we go."

"PUT IT ON PUT IT ON!" Sans had this terrible habit of doing everything as slowly as he possibly could. The urging only seemed to make him slower-perhaps because the pressure was tripping him up? Although with the way he was chuckling he was probably just being a jerk. "SAAAANS."

"okay okay." The sleeves easily covered his hands, and he had to roll the up a little to make his fingers visible. The end of the labcoat just managed to trail on the ground. But when he was all set he spun around a little to show off. "what do you think?"

"SANS YOU ARE A SCIENTIST NOW." Papyrus went in for another hug, squishing his brother who looked even smaller in such a big lab coat. "-YOU LOOK SO COOL!" And then, he wasn't proud of it, but a spark of jealousy shot through him at that, and he said, impulsively, "YOU SHOULD LET ME TRY IT ON!"

There was the sound of the front door closing faintly distant from downstairs.

"- _you_ wear it?" And then for one of the few times in his life Papyrus saw the grin on Sans' face almost completely drop off. Only for a second-briefly enough that if he'd blinked-if he'd had to blink-he'd have missed it. And he instantly regretted his impetuousness as he saw him glance towards the door. "…uh. …i dunno if that's a…good idea."

"OH-OH WELL THAT'S OKAY! IT'S YOUR COAT NOT MINE! BESIDES, I ALREADY HAVE LOTS OF COATS." He does a very good job of masking his disappointment.

"yeah. yeah you do. and i don't-want him to see you in this one. that's all."

Before Papyrus could ask what that meant, he heard Gaster call out to them from the living room, "[Boys?]" Then he had to run to the door and answer the call so he didn't think they'd run off somewhere.

While he did so Sans sighed and slipped off the labcoat, folding it up back inside the box.

* * *

 **Author's Note** : My activity speed may go down in the next few weeks-my real world obligations are starting to come to a head. Just as a warning.

I know I've said this already but it's really fun watching people speculate-I already know how everything is going to pan out so it's nice to see other people's anticipation.


	12. Arc IV Chapter 1

Arc IV: The Blasters

Chapter I

* * *

"Arbogast, you cannot stand at your full height, you will not fit into the picture."

"Right, right, I can slouch."

"-Sans you are the shortest so you go in the front."

"gee thanks."

Gaster peered out at them from behind the camera tripod, good eye narrowing slightly. "…? You are welcome?"

Sans grinned and waved his hand a little dismissively, straightening out the lab coat as he made his way to the front and center of the group. "never mind, doc."

"…Right. -Dr. Likker try to closing your eyelids a little, the shine from your eyes is throwing off my lighting system."

"I don't have any eyelids, W.D."

"Then use your hands or something."

Amid a couple jostling elbows and rearranging, Gaster let out a small growl, pinching just above his nasal hole. "Taking pictures should not be this difficult…Where is Alphys?"

She hadn't shown up for work today. Perhaps he'd assumed that she was merely late, but then she didn't show up later on either. Sans looked at the confusion of his colleagues before raising his hand. "she's out sick. picked up a bug the other day."

Or so she claimed.

Gaster snorted, expression darkening just a little. "Well that is what you get when you spend so much time at the dump, isn't it? I guess she doesn't get to be in the picture."

"i guess so."

The team working in the laboratory, minus Alphys, wasn't particularly large. But then neither was the viewfinder on Dr. Gaster's camera. In the front was Sans, teeth bared in his usual, skeleton grin. Just next to him were Doctors Likker and George, one of whom was in his usual bug-eyed stare and the other smiling as though he'd eaten something foul just before. And then behind them, with his jagged smile going up his entire head, was Dr. Arbogast.

"Alright, now hold still all of you." Back behind the camera Gaster went.

There were no announcements of "smile" or "say cheese"-just a sudden flash, and the click and _whirr_ of a camera producing its picture. After another few shots finally Gaster gestured for them all to move, and there were some collective sighs of relief and chattering. As the others began to wander back to their stations Sans took a step towards his desk-smaller than the others. Made using any spare equipment they had lying around, though Asgore was footing the bill for a new computer.

A holed hand waved in front of his face. "[I am not finished with you yet.]"

Sans sighed at the flip to wingding but stopped in his tracks. "what do you want, doc?"

"[Your photo for your badge.]"

The shorter skeleton blinked. For the past week he'd had above his name on his security pass not a picture of himself but a little image of him that Papyrus had taken the initiative on drawing. "PEOPLE WON'T KNOW WHO YOU ARE!", he'd said.

"oh. …well, uh. finally. although um-i kind of like the picture i have now?"

Gaster tilted his head somewhat, putting his hands on his shoulders and physically moving Sans into place against the white backdrop he still had set up. "[Don't be ridiculous. This will only take a minute. Five, counting the time it will take for you to get it in the badge …Or perhaps in your case ten with how lazy you are.]"

"hardy har har." He obediently stood still as the doctor moved the camera in closer before taking the head shot. Having the flash closer blanked out his eyes for a moment.

"[There we go.]" The picture made a little humming sound as it was printed out of the camera. Gaster handed the image off to Sans. "[Go to the paper slicer and get this the proper size. Then switch out that crude scribble.]"

"i think the crude scribble is cute. can't i keep this in here?"

"[No. Just because it is boring and menial doesn't mean you can get out of doing it. Now go on, I have other important matters to tend to. Now that Alphys is slacking off at home.]"

Sans almost tried to remind him that she wasn't slacking off, she was sick, but then she might have been lying anyway. He just blew out a long breath-one he didn't need because he had no lungs-and trudged off to head for the printing room.

It was a little off the beaten path. No one used it except for getting reports around. Which by itself didn't sound too complicated but apparently King Fluffybuns liked to have a little color and flash in the papers. Made it easier for him to read.

As he passed the vending machine he punched in one of buttons without really thinking about it, hearing a small beep as the machine protested the lack of payment.

Still full of chisps.

Finally he made his way there, flicking on a light and waiting as it fizzled to life.

The paper slicer was off to the side on the counter, surrounded by bits of paper scrap that no one had thrown away. Sans sighed, lining up his picture on the surface of it. Or trying to. Every time he was about to bring down the blade his fingers would nudge it just a little off the line and he'd have to line it back up.

Maybe he could cut the photo in half and lie and pretend that he hadn't messed it up on purpose. And then keep using the drawing. So Papyrus didn't have to look on his badge and frown and ask where his drawing went.

…Or maybe he'd just look at it and cheer that it looked all professional like he was a real scientist and it wasn't all some stupid game of pretend.

Whatever.

Making a big deal out of nothing.

The edges weren't completely even but eventually the sides were gone and it was small enough to fit inside the plastic slot on the badge. It took a bit of maneuvering. It was especial tricky because he'd opted to leave the original drawing inside, underneath the more professional looking photo. But eventually it was in there, and he turned it around to give it a once-over. See if it looked like the one Dr. Gaster used.

Sans the skeleton.

He shook his head, chuckling lightly and then heading back to the lab room.

* * *

"[Sans we are not calling them 'Gaster Blasters'.]"

Gaster heard his new coworker giggling behind him and sighed, erasing the image on their whiteboard with a sweep of his sleeve.

"[I knew I shouldn't have shown you a picture before giving you the rest of the details. We are calling them Energy Manipulation Cannons.]"

"aw come on doc."

"[They are _weapons_ , they are not toys.]" He considered himself fortunate that they were the only ones in the lab at this hour. No one else to overhear the embarrassing nickname. "[Besides, you know how Asgore is. If we introduce him to them through that name he'll never want to call them anything else.]"

Sans tilted his head slightly, hands in his pocket. "and that's a bad thing how?"

Gaster's working eye narrowed and Sans put his hands up, lightly waving them.

"alright alright, just tell me how we're gonna get it to work."

"[Well-]" Gaster began scrabbling out some notes on the board-starting in wingding before suddenly realizing that Sans couldn't read it and begrudgingly going back to aster. "[I have been preparing a device that can be used to sort of…implant the ability into any subject that I choose. -The process is a little more complicated than that but for simplicity's sake that is what it does.]"

"sounds fancy."

"[…Fancy is not the adjective I would use.]" He paused, erasing some text and making a crude sketch of the machine that he had stashed away in a far office of True Lab. "[There are some stipulations to using it, of course, otherwise I would have every monster in the underground installed with a cannon. First of all being that the process is…excruciating?]"

Sans took a step back, brow lifting slightly. "…excruciating, question mark?"

"[Well, I have not actually been able to use it, yet. That is just an educated assumption. You see I derived the cannon's properties from my own genetic structure, so it only works on…skeletons. And they have to be very magically robust skeletons at that.]"

There was a pause as the words sunk in and he turned back to his charge.

"[-This is partly why I was so excited when I first met you-another pair of skeletons with such precocious abilities.]"

"oh. …this is…what you intended all along, isn't it?" The curve of Sans' smile began to wane. Hands slipping out of his pockets to hang limply at his side. "…for me and papyrus."

"[You mean for Papyrus and _I_.]" His correction only seemed to make the suddenly tense atmosphere even worse, and Gaster sighed. Turning back to erase the whiteboard again. His sleeve was smudged and dark with black dry-erase marker. "[For you two, yes. –You did know that, didn't you? Or at least you suspected it? I can't believe this is the first time such a thing has crossed your mind.]"

"…i guess this isn't nearly as horrible as what i'd been thinking you had in mind."

"[That's the spirit.]" Gaster glanced back, going to put his hand on Sans' thin, bony shoulder. "[Yes.]"

"this is the thing you want me working on."

"[Of course. You're the only person I can-trust with this.]"

"…great."

The half-hearted way that Sans responded made Gaster the slightest bit uneasy for some reason. Like he didn't view this as the opportunity it was. He wanted him to be on board. He wanted his full energy towards it. Whatever energy there was lurking inside of him.

"[It doesn't bother you, does it? …Things actually turned out much better for you, you know. Now instead of being a subject to experiment on, you get to be a participating researcher.]"

That did seem to perk him up, surprisingly. Making that light noise that could be mistaken for laughter, if one didn't know what Sans' actual laugh sounded like. "…participating researcher, huh?"

"[Oh yes. I am excited to work _with_ you, not using you. You would assist me with calibrating the machine to make the process easier and more efficient, and develop usage of the actual cannon. Not aid that would be useful from a mere subject.]"

"…yeah? -yeah i guess i see what you mean." The smile returned, though hesitant and small. "i'm sure i can pick up on it all lickety-split, ay? like finding my way around in the core."

"[Precisely.]" Perhaps he should have gone for flattery years ago. Ah, well. Gaster started to move towards the exit into the hallway, gesturing for Sans to follow. "[We are not going to begin anything at this point but I am going to introduce you to the machine to better explain how this is going to work.]"

" _introduce me to the machine_?" Sans began to laugh again, and, encouraged, Gaster picked up the pace. "we gonna exchange names?"

"[Oh hush.]"

The lights flickered and wavered ominously as they walked through, not that the scientist paid any mind to it. The lab was always a little creepy when the others left-when it was just him. And now, Sans. Hm. Maybe that made it less so.

In the far removed corner, past some makeshift firing ranges and botany labs, he punched in the code for his personal technology lab. Quietly leading Sans inside. The lighting was much better in here-so bright that everything inside could be clearly seen, in fact. The both of them had to pause, let their vision adjust to the brightness.

"jeez you're a real pack rat, aren't you?"

The place was filled with junk.

-Not that Gaster saw it that way.

The countertops were not visible from all of the various machinery and parts that littered the room Half-finished inventions that were overtaken by more pressing projects, parts for ongoing ones that couldn't yet be installed. The only thing that really qualified as garbage in his mind were the pieces of a rubix cube that he hadn't been able to solve, strewn somewhat over the tile floor.

"[Nonsense. All of this has to go somewhere, doesn't it? I certainly can't keep it at the house.]"

In the corner was a mechanical base-looking like mere scrap at the moment, but still he quickly pulled a tarp over it before Sans could get a good look. "[Anyway, the machine there in the side-We're going to move this out somewhere less crowded, so that it can be used properly. I installed wheels. I figured you would approve of it requiring less _work_ to move.]"

"har har, you've got a really one-track joke mind, don't you?"

"[So do you, if Papyrus is to be believed.]" Gaster gave him a bit of a smirk, wrapping his thin bony fingers around the frame of the magic injector and slowly starting to pull it from its position. "[-Hold the door open, would you?]"

"sure." The wheels squeaked unbearably as it only just barely made it through the door-Gaster huffing slightly from the exertion. Mobile it may be, but the thing was still heavy. Rather than assist once he no longer had to hold the door open Sans just trailed along behind, hand in his pockets. "hey, uh-speaking of. this project's just gonna be the two of us, right? no one else?"

Gaster's broken eye dropped as he looked back, smile arching in its crooked way. "[Why would I need anyone else? We two are the only people this machine will work on, and we certainly don't need someone else to write notes. You are full of such unnecessary questions, Sans.]"

"hah. yeah." The taller skeleton waited for a self-degrading pun. It did not come. "nah, i mean are we gonna-you know, involve…" When Gaster looked back again Sans' eyes wavered, glancing briefly down at his new security badge, and then he shrugged "aw forget it. do i gotta keep this a secret, i mean?"

"[A secret?]" It was something that he'd briefly considered, surely. When given a choice between exposing his work to the world and hiding it behind closed doors, he would always prefer the latter. Just because sometimes he wasn't understood. Sometimes he was misread. And sometimes, some people, who he would not think about, tried to steal credit for his work.

But ultimately, trying to keep his voice as casual as possible, he replied, "[…No. No you do not have to keep it a secret. Although I would like that you not _broadcast_ it to your little friends.]"

"you mean i can't text everyone all your calculations?"

"[Do not joke with me, Sans, you know I have no sense of humor.]"

The testing room was ultimately about the same size as Gaster's personal tech lab, but it wasn't filled up with other projects to hog space. He carefully slotted it against the wall, grabbing a chair from the side and positioning it in front of the machine. It was only then that Sans took a step forward to provide a stabilizing influence, grinning as he usually did.

He flinched when Gaster put his hand on his shoulder.

"[You will make me proud. I know you will.]"

"…sure. thanks doc."

* * *

 **Author's Note** : I'm so sorry this chapter took so much longer than the others. Please know I am _not_ dropping this fic. I have written so much for what comes next already, there's no way I could. But my life is picking up and I have several things on the burner. Including working on a future story collection I really hope I can get through. It doesn't help that when I did get some clear inspiration, I ended up getting inspired to write the chapter _after_ this one.


End file.
